MR findings of the spinal paraganglioma : report of three cases

Extraadrenal paragangliomas involving the spine is less common and usually takes the form of intradural compression of the cauda equina. The authors report three cases of spinal paragangliomas resulting in extradural spinal cord compression and their MR findings. The MR imaging revealed a well-demarcated extradural mass with low to intermediate signal intensity on T1-weighted images and intermediate to high signal intensity on T2-weighted images compared to paravertebral muscles. After Gd-DTPA administration, heterogeneous and intense enhancement was found. Multiple punctate and serpiginous structures of signal void due to high-velocity flow were noted around and within the tumors on all sequences. In one case, the signal void structures were well corresponded with feeding arteries on angiography. These may be the characteristic findings of the extraadrenal paraganglioma involving the spine.

Comparison of IY81149 with omeprazole in rat reflux oesophagitis

1. This study was aimed at evaluating the effects of IY81149[2-[[(4methoxy-3-methyl)-2-pyridinyl]methylsulfinyl]-5-(1H-pyrrol-1-yl)-1H-benzimidazole], a new proton pump inhibitor, on the development of the surgically induced reflux oesophagitis, on gastric secretion and on lipid peroxidation which is a marker of oxidative stress. Omeprazole was used as a reference drug. We furthermore investigated the influence of quercetin and desferrioxamine (DFO) on the development of the surgically induced reflux oesophagitis in rats on gastric secretion and on lipid peroxidation. 2. IY81149 and omeprazole significantly prevented the development of reflux oesophagitis and gastric secretion in a dose-dependent manner. The ED50 values of IY81149 for inhibition of oesophagitis and volume of gastric secretion were lower than of omeprazole (5.7 vs. 14.2 micromol, 15.3 vs. 24.0 micromol, respectively). IY81149 was also more potent in the acid output inhibition with an ED50 of 6.8 micromol compared with 20.8 micromol of omeprazole. 3. Malonyldialdehyde (MDA) content, the end product of lipid peroxidation, increased significantly in the oesophageal mucosa after the induction of reflux oesophagitis. IY81149 and omeprazole significantly and dose-dependently prevented lipid peroxidation. Quercetin (200 mg kg-1, p.o.) and DFO (800 mg kg-1, i.d.) significantly prevented the development of reflux oesophagitis and inhibited the lipid peroxidation independent of their actions on gastric secretion. 4. This result suggests that IY81149 is comparable with omeprazole in the treatment of reflux oesophagitis.

Dose-response effect of oxygen on hyperinflation and exercise endurance in nonhypoxaemic COPD patients

Dynamic hyperinflation contributes to exertional breathlessness and reduced exercise tolerance in chronic obstructive pulmonary disease (COPD) patients. This study examined whether oxygen supplementation results in a dose-dependent decrease in hyperinflation associated with functional and symptomatic improvement. Ten severe COPD patients without clinically significant oxygen (O2) desaturation during exercise, and seven healthy subjects, performed five exercise tests at 75% of maximally tolerated work rate. Inspired oxygen fraction (FI,O2) was varied (0.21, 0.3, 0.5, 0.75 and 1.0) among tests in a randomized order. Ventilation (V'E) was measured, and end-inspiratory (EILV) and end-expiratory (EELV) lung volume changes were assessed from inspiratory capacity manoeuvres. In the patients, compared to room air, endurance time increased with FI,O2=0.3 (mean+/-SEM 92+/-20%) and increased further with FI,O2=0.5 (157+/-30%). At isotime, compared to room air, there were significant reductions in dyspnoea score, EELV, EILV, V'E and respiratory frequency (fR) with FI,O2=0.3. Improved endurance time negatively correlated with change in EELV (r=0.48, p=0.002) and EILV (r=0.43, p=0.005). The dyspnoea rating decrease correlated with fR decrease. In healthy subjects, smaller V'E and fR decreases were observed at FI,O2=0.5, accompanied by more modestly increased endurance. Oxygen supplementation during exercise induced dose-dependent improvement in endurance and symptom perception in nonhypoxaemic chronic obstructive pulmonary disease patients, which may be partly related to decreased hyperinflation and slower breathing pattern. This effect is maximized at an inspired oxygen fraction of 0.5.

Bilateral neurotrophic keratopathy complicating Vidian neurectomy

PURPOSE

To present a case of bilateral neurotrophic keratopathy with miosis after bilateral Vidian neurectomy for vasomotor rhinitis.

METHODS

Observational case report.

RESULTS

A 68 year-old man presented with irritation and blurred vision in both eyes 2 weeks after bilateral Vidian neurectomy. Slit-lamp examination revealed a large epithelial defect, typical of neurotrophic keratopathy, in the inferior two-thirds of cornea in both eyes. Corneal sensitivity test with a Cochet-Bonnet anesthesiometer and electrical study of the blink reflex indicated bilateral trigeminal dysfunction. Both pupils were miotic, and tests with hydroxyamphetamine 1% and epinephrine 0.1% showed postganglionic sympathetic nerve damage. The corneal epithelial defects healed after 2 months of treatment with systemic prednisolone, vitamin B(12) and tarsorrhaphy.

CONCLUSION

Neurotrophic keratopathy associated with dry eye syndrome may be a serious complication of Vidian neurectomy.

Bone marrow aspiration, biopsy, and culture in the evaluation of HIV-infected patients for invasive mycobacteria and histoplasma infections

Bone marrow (BM) aspiration and biopsy are used commonly in clinical practice to diagnose invasive tissue infections caused by Mycobacterium avium intracellulare (MAC), Mycobacterium tuberculosis (TB), and Histoplasma capsulatum (HC) in patients with human immunodeficiency virus-1 (HIV) infection. However, the value of these invasive procedures relative to other diagnostic approaches has not been clearly defined. To determine the value of BM culture and BM histology in the diagnosis of opportunistic MAC/TB and HC infections in immunosuppressed patients with HIV, we retrospectively reviewed the records of 56 adult patients with HIV who underwent a single BM aspiration, biopsy, and culture because of unexplained fever and/or other clinical features suggestive of MAC/TB or HC infection. Thirty-two patients (57%) were ultimately diagnosed with MAC/TB or HC infection by positive cultures of BM, blood, sputum, or bronchoalveolar lavage fluid or by the histologic detection of organisms in biopsies of BM or other tissues. The diagnostic sensitivity of BM cultures was equal to that of blood cultures (20/32, or 63%). Granuloma and/or histologically apparent organisms were seen in BM biopsy specimens in 11 of 32 individuals (34%) ultimately diagnosed with MAC/TB or HC infections. Among these 11 cases, both granuloma and acid-fast staining organisms were found in the BM biopsy specimens of 2 individuals for whom both BM and blood cultures were negative. Certain clinical symptoms and signs at the time of BM examination were found by logistic regression analysis to be significantly associated with a subsequent diagnosis of MAC/TB or HC infections; these included high fever, long duration of febrile days prior to BM examination, and elevated direct bilirubin. In conclusion, while the diagnostic sensitivity of BM cultures was found to be no greater than that of blood cultures in detecting MAC/TB or HC infections in immunosuppressed HIV+ patients, histopathologic examination of BM specimens resulted in the relatively rapid identification of nearly one third of infected patients who underwent BM examination, and also identified infections in some patients who were culture negative. These findings support the continued use of BM aspiration, biopsy, and culture for the diagnosis of opportunistic MAC/TB or HC infections in immunosuppressed HIV+ patients, particularly when selected clinical features are present.

A hydrogen storage mechanism in single-walled carbon nanotubes

We have carried out systematic calculations for hydrogen-adsorption and -storage mechanism in carbon nanotubes at zero temperature. Hydrogen atoms first adsorb on the tube wall in an arch-type and zigzag-type up to a coverage of theta = 1.0 and are stored in the capillary as a form of H(2) molecule at higher coverages. Hydrogen atoms can be stored dominantly through the tube wall by breaking the C--C midbond, while preserving the wall stability of a nanotube after complete hydrogen insertion, rather than by the capillarity effect through the ends of nanotubes. In the hydrogen-extraction processes, H(2) molecule in the capillary of nanotubes first dissociates and adsorbs onto the inner wall and is further extracted to the outer wall by the flip-out mechanism. Our calculations describe suitably an electrochemical storage process of hydrogen, which is applicable for the secondary hydrogen battery.

Effects of IY-81149, a newly developed proton pump inhibitor, on gastric acid secretion in vitro and in vivo

The inhibitory effects of IY-81149 (2-[[(4-methoxy-3-methyl)-2- pyridinyl]methyl-sulfinyl]-5-(1H-pyrol-1-yl)-1H-benzimidazole, CAS 172152-36-2), a newly developed proton pump inhibitor (PPI) on gastric acid secretion were investigated in vitro and in vivo. In rabbit parietal cell preparation, IY-81149 irreversibly inhibited H+/K(+)-ATPase in dose-dependent manner with an IC50 of pump inhibitory activity of 6.0 x 10(-6) mol/l and that of omeprazole (CAS 73590-58-6) was 1 x 10(-4) mol/l at pH 7.4. On cumulation of 14C-aminopyrine in histamine stimulated parietal cells, the IC50 of IY-81149 was 9.0 x 10(-9) mol/l and that of omeprazole was 1.9 x 10(-8) mol/l. The inhibition rates of IY-81149 and omeprazole at a concentration of 1 x 10(-9) mol/l in human parietal cells were 137% and 64%, respectively. In pylorus-ligated rats, IY-81149 showed a 2-3 times stronger inhibitory activity than omeprazole against gastric acid secretion. The ED50 of IY-81149 and omeprazole administered intraduodenally was 1.6 mg/kg and 3.8 mg/kg. In the case of oral administration, the ED50 of IY-81149 and omeprazole was 1.94 mg/kg and 5.64 mg/kg, respectively. But after 24 h administration, the anti-secretory activity of IY-81149 was lower than that of omeprazole at all doses tested. In anesthetized rats, IY-81149 dose-dependently increased gastric pH which was lowered by histamine infusion. In the case of i.v. injection, the ED50 of IY-81149 and omeprazole was 1.2 and 1.4 mg/kg and in the case of i.d. administration, the ED50 of IY-81149 and omeprazole was 3.9 and 4.1 mg/kg, respectively. IY-81149 also significantly inhibited pentagastrin-stimulated gastric secretion. Its ED50 was 2.1 mg/kg and that of omeprazole was 3.5 mg/kg with i.d. administration. In the case of i.v. injection, IY-81149 was equipotent to omeprazole. IY-81149 also inhibited gastric acid secretion strongly in fistular rats. The ED50 of IY-81149 administered intraduodenally was 0.43 mg/kg and that of omeprazole was 0.68 mg/kg. In Heidenhain pouch dogs, the acid output was completely blocked at 0.3 mg/kg, 135 min after i.v. administration. Omeprazole showed a similar effect as IY-81149. The histamine induced increase of acid output in the Heidenhain pouch dog was blocked by 71% 150 min after oral administration of enteric-coated IY-81149 at a dose of 3 mg/kg, and omeprazole showed similar effects. In conclusion, IY-81149 revealed the characteristics as a strong proton pump inhibitor, and its potency against gastric acid secretion was superior to that of the reference drug, omeprazole.

Control of mitochondrial redox balance and cellular defense against oxidative damage by mitochondrial NADP+-dependent isocitrate dehydrogenase

Mitochondria are the major organelles that produce reactive oxygen species (ROS) and the main target of ROS-induced damage as observed in various pathological states including aging. Production of NADPH required for the regeneration of glutathione in the mitochondria is critical for scavenging mitochondrial ROS through glutathione reductase and peroxidase systems. We investigated the role of mitochondrial NADP(+)-dependent isocitrate dehydrogenase (IDPm) in controlling the mitochondrial redox balance and subsequent cellular defense against oxidative damage. We demonstrate in this report that IDPm is induced by ROS and that decreased expression of IDPm markedly elevates the ROS generation, DNA fragmentation, lipid peroxidation, and concurrent mitochondrial damage with a significant reduction in ATP level. Conversely, overproduction of IDPm protein efficiently protected the cells from ROS-induced damage. The protective role of IDPm against oxidative damage may be attributed to increased levels of a reducing equivalent, NADPH, needed for regeneration of glutathione in the mitochondria. Our results strongly indicate that IDPm is a major NADPH producer in the mitochondria and thus plays a key role in cellular defense against oxidative stress-induced damage.

Simulated shuttle egress: role of helmet visor position during approach and landing

BACKGROUND

We previously reported that carbon dioxide (CO2) rapidly accumulates in the helmet of the NASA Launch and Entry Suit (LES) during a simulated egress from the Space Shuttle following 6 min of visor-closed seated rest to simulate approach and landing. The purpose of this study was to determine if CO2 accumulation and walking time in the LES would be improved by helmet visor-open rather than visor-closed seated rest prior to the performance of the simulated egress.

METHODS

Wearing the LES, 12 male subjects performed 4 laboratory egress simulations consisting of 6-min seated rest, 2-min stand, and 5-min walk at 1.56 m x s(-1) (3.5 mph). During seated rest, subjects sat either with the visor open, breathing room air until the visor was closed on standing, or with the visor closed for the duration of the simulation. For all visor-closed operations 100%, O2 was supplied. The G-suit was either deflated (0.0 psi) or inflated to 1.5 psi. Inspired CO2 and walking time were measured. Data were analyzed at the end of seated rest, standing, and after 5 min of walking at 0.0 psi or after 2 min of walking at 1.5 psi (>90% of data available).

RESULTS

Walk time was not different following visor-open (0.0 psi: 5.0 +/- 0.0; 1.5 psi: 3.4 +/- 0.3 min) or visor-closed (0.0 psi: 4.8 +/- 0.2; 1.5 psi: 3.5 +/- 0.4 min) seated rest at either G-suit pressure. Inspired CO2 levels were not different between the two conditions during walking at 5 min at 0.0 psi (p = 0.50; Open: 4.39 +/- 0.14; Closed: 4.48 +/- 0.18%) or at 2 min at 1.5 psi (p = 0.53; Open: 3.59 +/- 0.12; Closed: 3.65 + 0.21%).

CONCLUSIONS

Visor position during seated rest immediately preceding the egress walk had no effect on inspired CO2 or walking time.

Protein-protein interaction of FHL3 with FHL2 and visualization of their interaction by green fluorescent proteins (GFP) two-fusion fluorescence resonance energy transfer (FRET)

LIM domain proteins are found to be important regulators in cell growth, cell fate determination, cell differentiation and remodeling of the cell cytoskeleton. Human Four-and-a-half LIM-only protein 3 (FHL3) is a type of LIM-only protein that contains four tandemly repeated LIM motifs with an N-terminal single zinc finger (half LIM motif). FHL3 expresses predominantly in human skeletal muscle. In this report, FHL3 was shown to be a novel interacting partner of FHL2 using the yeast two-hybrid assay. Furthermore, site-directed mutagenesis of FHL3 indicated that the LIM2 of FHL3 is the essential LIM domain for interaction with FHL2. Green fluorescent protein (GFP) was used to tag FHL3 in order to study its distribution during myogenesis. Our result shows that FHL3 was localized in the focal adhesions and nucleus of the cells. FHL3 mainly stayed in the focal adhesion during myogenesis. Moreover, using site-directed mutagenesis, the LIM1 of FHL3 was identified as an essential LIM domain for its subcellular localization. Mutants of GFP have given rise to a novel technique, two-fusion fluorescence resonance energy transfer (FRET), in the determination of protein-protein interaction at particular subcellular locations of eukaryotic cells. To determine whether FHL2 and FHL3 can interact with one another and to locate the site of this interaction in a single intact mammalian cell, we fused FHL2 and FHL3 to different mutants of GFP and studied their interactions using FRET. BFP/GFP fusion constructs were cotransfected into muscle myoblast C2C12 to verify the colocalization and subcellular localization of FRET. We found that FHL2 and FHL3 were colocalized in the mitochondria of the C2C12 cells and FRET was observed by using an epi-fluorescent microscope equipped with an FRET specific filter set.

Immunolocalization of zona pellucida antigens in the ovarian follicle of dogs, cats, horses and elephants

A comparative evaluation of the location of immunoreactive porcine zona pellucida (pZP) glycoproteins was performed with polyclonal rabbit anti-pZP antibodies on ovarian sections of the dog, cat, horse, and elephant. For this, formalin (light microscopy) and glutaraldehyde (transmission electron microscopy [TEM]) fixed ovarian sections were incubated with antibodies raised against highly purified pZP. Staining patterns were determined with diaminobenzidine (DAB) at the light level. The dog ZP had a distinct staining distribution that is characterized by intense staining around the periphery of the ZP and the oolemma and less dense staining throughout the width of the ZP. In dog follicles that contained multiple oocytes, there were oocytes of identical and dissimilar stages. Cat ovarian sections showed uniform staining of the ZP. Horse results showed uniform staining of ZP and ooplasm, and granulosa cells (GC). Elephant sections showed staining of the ZP with dense staining at the oolemma, as well as staining of the ooplasm. In all species the staining of the ZP was not evident until GC differentiation. In all cases there was no staining of ovarian tissue with control normal rabbit serum. Specific staining patterns of ZP were evaluated by TEM and immunogold staining. The immunogold-linked anti-pZP antibodies stained the ZP matrix in all species. There was staining of ooplasm organelles suggesting that ZP secretion originates from the oocyte of the dog and cat. In addition, follicular and ZP measurements were taken that allowed accurate characterization of follicle stage. These findings suggest that in all four species the ZP is recognized by anti-pZP antibodies and there is also evidence to suggest the possible origins of ZP glycoproteins.

Characterization of tissue-specific LIM domain protein (FHL1C) which is an alternatively spliced isoform of a human LIM-only protein (FHL1)

We have cloned and characterized another alternatively spliced isoform of the human four-and-a-half LIM domain protein 1 (FHL1), designated FHL1C. FHL1C contains a single zinc finger and two tandem repeats of LIM domains at the N-terminus followed by a putative RBP-J binding region at the C-terminus. FHL1C shares the same N-terminal two-and-a-half LIM domains with FHL1 but different C-terminal protein sequences. Due to the absence of the exon 4 in FHL1C, there is a frame-shift in the 3' coding region. Sequence analysis indicated that FHL1C is the human homolog of murine KyoT2. The Northern blot and RT-PCR results revealed that FHL1 is widely expressed in human tissues, including skeletal muscle and heart at a high level, albeit as a relatively low abundance transcript in brain, placenta, lung, liver, kidney, pancreas, and testis. In contrast, FHL1C is specifically expressed in testis, skeletal muscle, and heart at a relatively low level compared with FHL1. The expression of FHL1C transcripts was also seen in aorta, left atrium, left, and right ventricles of human heart at low level. Immunoblot analysis using affinity-purified anti-FHL1C antipeptide antibodies confirmed a 20 kDa protein of FHL1C in human skeletal muscle and heart. Unlike FHL1B, which is another FHL1 isoform recently reported by our group and localized predominantly in the nucleus [Lee et al., 1999], FHL1C is localized both in the nucleus and cytoplasm of mammalian cell.

S-adenosylmethionine protects post-ischemic mitochondrial injury in rat liver

BACKGROUND/AIMS

S-adenosylmethionine (SAM) is a thiol-containing compound with known therapeutic affects on cholestasis and hepatotoxicity. The aim of this study was to investigate the effect of SAM on the prevention of mitochondrial injury induced by hepatic ischemia and reperfusion.

METHODS/RESULTS

Rats were subjected to 60 min of hepatic ischemia and 1 and 5 h of reperfusion. 2 h prior to ischemia, the animals received either vehicle or SAM intraperitoneally. In the vehicle-treated ischemic animals, serum aspartate aminotransferase levels increased at 1 h and again at 5 h of reperfusion and were reduced by SAM pre-treatment. Similarly, mitochondrial lipid peroxidation was elevated in the vehicle-treated group, but this elevation was attenuated by SAM. In contrast, mitochondrial glutamate dehydrogenase activity and reduced glutathione concentration both decreased in the vehicle-treated group, and this decrease was also inhibited by SAM. Hepatic ATP levels in the vehicle-treated rats were found to be 42% lower 5 h after reperfusion, however, treatment with SAM elevated these ATP levels. SAM treatment increased the concentration of adenosine but inhibited the accumulation of hypoxanthine in the ischemic liver.

CONCLUSION

SAM protects against mitochondrial injury, which prevents mitochondrial oxidant stress and improves ischemia-induced hepatic energy metabolism.

Novel method for enhancing permeate flux of submerged membrane system in two-phase anaerobic reactor

A two-phase anaerobic reactor system with a submerged membrane in the acidogenic reactor was designed for the enhancement of organic acid conversion and methane recovery. A submerged membrane system in a two-phase anaerobic reactor was tested to increase the sludge retention time (SRT) of acidogen and to enhance the solid separation. The pilot plant experiment was performed for piggery wastewater treatment for a year. The membrane material used was mixed esters of cellulose of 0.5 micron pore size. COD removal efficiency was 80% and the methane production showed 0.32 m3/kg COD removed for the submerged membrane system in the anaerobic digester. As the cake resistance of the membrane caused a serious problem, a stainless-steel prefilter and air backwashing methods were applied to minimize the cake resistance effectively. Among the tested prefilters, the 63 microns pore prefilter showed the best performance for reducing cake resistance and a successful long-term operation. By cleaning with alkali first and acidic solutions later, the permeate flux decreased by long-term operation was recovered to 89% of that with a new membrane.

Use of hematopoietic progenitors in whole blood to support dose-dense chemotherapy: a randomized phase II trial in small-cell lung cancer patients

PURPOSE

Small-cell lung cancer (SCLC) is exquisitely chemosensitive, but few patients are cured by conventional chemoradiotherapy. Recent studies suggest that increased cytotoxic dose-intensity might improve survival. In this randomized phase II study, we tested the feasibility of dose intensification using sequential reinfusion of hematopoietic progenitors in whole blood.

PATIENTS AND METHODS

SCLC patients with a favorable prognosis were treated with six cycles of ifosfamide, carboplatin, and etoposide (ICE), at 4-week (standard treatment) or 2-week (intensified treatment) intervals. Intensified treatment was supported by daily subcutaneous filgrastim injections and reinfusion of 750 mL of autologous blood collected immediately before each cycle.

RESULTS

Fifty consecutive patients were randomized to standard (n = 25) or intensified (n = 25) ICE. A total of 94% completed at least three treatment cycles, and 70% completed six cycles; 96% of treatments were given at full dose. The planned dose-intensity was 1.0 for standard and 2.0 for intensified ICE. The median received dose-intensity for cycles 1 through 3 was 0.99 (range, 0.33 to 1.02) for the standard treatment arm and 1.80 (range, 0.99 to 1.97) for the intensified treatment arm (P <.001). Over all six cycles, the median received dose-intensity was 0.95 (range, 0.17 to 1.03) for the standard treatment arm and 1.60 (range, 0.60 to 2.01) for the intensified treatment arm (P <.001). Febrile neutropenia was more common on the standard treatment arm (84% v 56%), resulting in more days of intravenous antibiotics (median, 10 v 3 days; P =.035). Transfusion requirements were similar in the two groups.

CONCLUSION

Sequential reinfusion of hematopoietic progenitors in whole blood can safely support substantial increases in dose-intensity of ICE chemotherapy for SCLC.

Protective effect of allopurinol on hepatic energy metabolism in ischemic and reperfused rat liver

Reactive oxygen species generated by xanthine oxidase during reperfusion of ischemic liver might in part be responsible for ischemic organ injury. In normothermic ischemia/reperfusion rat model, we investigated whether allopurinol pretreatment improved ischemia-induced mitochondrial dysfunction. Rats were subjected to 60 min of hepatic ischemia and to 1 h and 5 h of reperfusion thereafter. At 18 h and 1 h before ischemia, the animals received 0.25 mL of either saline or allopurinol (50 mg/kg) i.p. In saline-treated ischemic rats, serum aspartate aminotransferase levels increased significantly at 5 h (4685 +/- 310 IU/L) and were significantly reduced with allopurinol pretreatment. Similarly, mitochondrial lipid peroxidation was elevated in the saline-treated ischemic group, but this elevation was prevented by allopurinol. In contrast, mitochondrial glutamate dehydrogenase activity and ketone body ratio decreased in the saline-treated group, but this decrease was also inhibited by allopurinol. Hepatic ATP levels in the saline-treated rats were 42% lower 5 h after reperfusion. However, treatment with allopurinol resulted in significantly higher ATP levels. Allopurinol treatment preserved the concentration of AMP in ischemic liver but inhibited the accumulation of xanthine in reperfused liver. Our findings suggest allopurinol protects against mitochondrial injury, which prevents a mitochondrial oxidant stress and lipid peroxidation and preserves the hepatic energy metabolism.

Simulated shuttle egress: comparison of two Space Shuttle protective garments

BACKGROUND

In a previous study from our laboratory, we observed carbon dioxide (CO2) accumulation in the helmet of the NASA Launch and Entry Suit (LES) during a simulated emergency egress from the Space Shuttle. Of 12 subjects, 8 were unable to complete the egress simulation with a G-suit inflation pressure of 1.5 psi. The purpose of this report was to compare CO2 accumulation and egress walking time in the new Advanced Crew Escape Suit (ACES) with that in the LES.

METHODS

Four male subjects who previously were unable to complete the egress in the LES performed a simulated egress while wearing the ACES with the G-suit inflated to 1.5 psi. The egress simulation consisted of 6 min of seated rest, 2 min of standing, and 5 min of walking on a treadmill at 1.56 m x s(-1) (3.5 mph) and 0% grade. The helmet visor was closed with the subjects receiving 100% oxygen throughout the simulation. Inspired CO2 and walking time were measured.

RESULTS

The rate of CO2 accumulation was significantly less (ACES: 0.53 +/- 0.03, LES: 1.07 +/- 0.15 %CO2 x min(-1); p = 0.05) and walk time was greater in the ACES (ACES: 5.0 +/- 0.0, LES: 2.7 +/- 0.2 min; p = 0.002).

CONCLUSIONS

Changes in the design of the ACES from the LES resulted in a decreased rate of CO2 accumulation and an improved egress walking time compared with the LES.

Removal of Cu(II) and Cd(II) from aqueous solution by seafood processing waste sludge

Dried waste slurry generated in seafood processing factories has been shown to be an effective adsorbent for the removal of heavy metals from dilute solutions. Characterization of the sludge surface with scanning electron microscope and X-ray microanalyzer were carried out to evaluate the components on the sludge surface that are related to the adsorption of metal ions. Aluminum and calcium, as well as organic carbon are distributed on the surface of sludge. Alkalimetric titration was used to characterize the surface acidity of the sludge sample. The surface acidity constants, pKa1s and pKa2s, were 5.80 and 9.55, respectively. Batch as well as dynamic adsorption studies were conducted with 10(-5) to 5 x 10(-3) M Cu(II) and Cd(II). A surface complexation model with the diffuse layer model successfully predicted Cu(II) and Cd(II) removals in single metal solutions. Predictions of sorption in binary-adsorbate systems based on single-adsorbate data fits represented competitive sorption data reasonably well over a wide range of conditions. The breakthrough capacity found from column studies was different for each metal ion and the data reflect the order of metal affinity for the adsorbent material very well.

Microsatellite instability at AAAG repeat sequences in respiratory tract cancers

We surveyed the occurrence of novel alleles at microsatellite sequences in non-small cell lung cancers (NSCLC) using 61 tetranucleotide repeat markers. The presence of at least one new allele, consistent with microsatellite instability (MSI), was observed in 26 of 61 (43%) markers involving 30 of 47 (64%) NSCLC. Twelve of the 26 markers detected new alleles in 2 or more tumors and 11 of these 12 markers contained an AAAG repeat sequence. Using this panel of 12 markers, MSI was detected in 24 of 47 (51%) NSCLC and 10 of 18 (56%) head and neck cancers but was only observed in 8 of 38 (21%) bladder cancers and 3 of 25 (12%) kidney cancers. Our results suggested that about 50% of respiratory tract cancers exhibited microsatellite instability predominantly at AAAG sequences. This distinct type of instability was termed EMAST for elevated microsatellite alterations at selected tetranucleotide repeats. The identification of markers with EMAST should have potential application for the molecular detection of respiratory tract cancers.

Interferon and ribavirin vs interferon alone in the re-treatment of chronic hepatitis C previously nonresponsive to interferon: A meta-analysis of randomized trials

CONTEXT

Hepatitis C is the leading cause of chronic liver disease in the United States. Several trials have found that interferon and ribavirin combination therapy is more efficacious than interferon monotherapy for previously untreated patients and those who relapsed after prior interferon monotherapy, but its effectiveness for nonresponders to prior interferon monotherapy is unclear.

OBJECTIVE

To assess the efficacy and safety of interferon and ribavirin vs interferon alone for treatment of patients with chronic hepatitis C who previously did not respond to interferon monotherapy.

DATA SOURCES

A systematic search was performed using MEDLINE and the Science Citation Index for publications from 1966 to December 1999. A manual reference search and a manual review of relevant specialty journals also were performed, and input from clinical hepatology experts was sought.

STUDY SELECTION

Included studies were randomized, controlled clinical trials comparing interferon and ribavirin with interferon alone and reporting virological and biochemical outcomes after a follow-up period. Of 50 identified studies, 12 trials (941 patients) were included in the analysis.

DATA EXTRACTION

Two investigators reviewed trials independently for methods, inclusion and exclusion criteria, and outcomes. Disagreements were resolved by discussion. Abstracted data included study and patient characteristics and virological, biochemical, and histological outcomes. A quality evaluation questionnaire was used to score studies.

DATA SYNTHESIS

The pooled virological response rate for combination therapy was 14% (95% confidence interval [CI], 11%-17%), with a risk difference favoring combination therapy of 7% (95% CI, 2%-13%). Use of interferon alfa-2a/2b and ribavirin, 1000 to 1200 mg/d, was associated with a pooled virological response rate of 18% and a risk difference of 16% (95% CI, 11%-21%). When interferon alfa-n/n3 and a lower dosage of ribavirin (600-800 mg/d) were used, the risk difference was 0% (95% CI, -7% to 7%). Combination therapy was associated with more adverse effects and an increased rate of discontinuation of treatment compared with interferon monotherapy.

CONCLUSIONS

For chronic hepatitis C that is nonresponsive to prior interferon monotherapy, combination therapy is more effective than re-treatment with interferon alone. Response rates remain less than 20% even in the most responsive subgroups, demonstrating a need for better therapeutic options.