Biomedical subjects

S M Lee

Publications and source records attributed to S M Lee.

At least 73 records · Page 4Linked to original sources

PubMed2001

Functional characteristics of a new electrolarynx "Evada" having a force sensing resistor sensor.

Electrolarynxes have been used as one of the rehabilitation methods for laryngectomees. Earlier electrolarynxes could not alter frequency and intensity simultaneously during conversation. Recently, we developed an electrolarynx named "Evada" (prototype so far) using a force sensing resistor (FSR) sensor that can control both frequency and intensity simultaneously during conversation. Employing three types of electrolarynxes (Evada, Servox-inton, Nu-vois), this study was undertaken to examine the functional characteristics of Evada for the normal control group and for laryngectomess. Five laryngectomees and five normal adults were asked to express three sentences (declarative sentence, "You stay here.", interrogative sentence, "You stay here?", and imperative sentence, "You! Stay here.") using three types of electrolarynxes. Frequency and intensity changes between the first and last vowels in the three sentences were calculated and analyzed statistically by paired t test. The frequency changes in the interrogative and imperative sentences were more prominent in Evada than in Servox-inton and Nu-vois. The intensity changes in the interrogative and imperative sentences were also more prominent in Evada than in Servox-inton and Nu-vois. Evada controls frequency and/or intensity by having the subject press the control button(s). Therefore, Evada appears to be better at producing intonation and contrastive stress than Nu-vois and Servox-inton.

Equipment Design↗

PubMed2001

Naltrexone dampens ethanol-induced cardiovascular and hypothalamic- pituitary-adrenal axis activation.

Alcohol ingestion activates the autonomic nervous system and the hypothalamic-pituitary-adrenal axis. This study examined naltrexone effects on alcohol-induced increases in physiological responses and their association with alcohol liking. Using a within-subjects design, heavy drinking men (N = 19) were maintained on each of three naltrexone doses (0, 50, and 100 mg, p.o.) over an 8-day inpatient stay. Within each naltrexone dose, subjects had three alcohol challenge sessions (none, moderate, high) in random order. Autonomic, subjective and endocrine measurements were collected regularly prior to and following alcohol administration. High-dose alcohol ingestion increased heart rate, diastolic blood pressure, skin temperature, ACTH, cortisol and liking of drink effects; responses following the moderate alcohol dose were less consistent. Naltrexone significantly dampened alcohol-induced increases in heart rate, diastolic blood pressure, hormone levels and subjective liking of drink effects. This dampening of cardiovascular and hormonal responses may contribute to the therapeutic effectiveness of naltrexone for reducing alcohol liking and decreasing relapse in alcohol-dependent persons.

Adult↗

PubMed2001

Immunologic recovery after autologous blood stem cell transplantation in patients with AL-amyloidosis.

We prospectively studied absolute lymphocyte (ALC) and monocyte counts (AMC), lymphocyte subsets and proliferative in vitro responses to mitogen and antigen in 12 patients with AL-amyloidosis (AL) undergoing autologous blood stem cell transplantation (SCT) with high-dose i.v. melphalan. Myeloid and lymphoid recovery (>500 per microl) occurred in a median of 10 days post SCT. While there was a continuous decline in the number of CD4+ T cells at 3 months, ALC, AMC, B cells (CD19+), CD8+ T cells, and NK cells (CD16+/56+) returned to baseline. While T cell proliferative responses to phytohemagglutinin (PHA) remained depressed, B cell function measured by the proliferative response to staphylococcal antigen returned to baseline by 3 months. To supplement our findings, we retrospectively evaluated ALC, AMC and serum immunoglobulin levels in a separate group of patients treated with the same protocol at our institution. ALC and AMC recovery was similar to the pattern observed in the initial study group. Immunoglobulin levels remained within normal ranges at 3 and 12 months after SCT. Of 50 patients who were followed for a minimum of 1 year following SCT, seven (14%) developed shingles and one (2%) had PCP pneumonia. In conclusion, cellular immune function, reflected by absolute numbers of CD4+ T cells and PHA responsive T cell proliferation, is significantly suppressed at 3 months after SCT in patients with AL, and this post-transplant immunosuppression is associated with a low but clinically meaningful occurrence of opportunistic infections typical of T cell immunosuppression.

Adult↗

PubMed2001

A high-dose pulse steroid regimen for controlling active chronic graft-versus-host disease.

Corticosteroids remain essential for controlling active chronic graft-versus-host disease (cGVHD). However, the optimum dose and administration schedule is unknown. We have reviewed our results in 61 patients with severe refractory cGVHD who were treated with a high-dose pulse steroid regimen (PS) consisting of methylprednisolone at 10 mg/kg per day for 4 consecutive days, with subsequent tapering doses. After 4 days, all patients received a course of additional immunosuppressive therapy. The median age of the 56 patients who were evaluable for response was 32 years (range, 0.2-57 years). Patients had failed a median of 2 (range, 1-5) treatments prior to the PS. The median follow-up for 45 surviving patients after PS was 1.5 years. The probability of survival at 1 year and 2 years after PS was 88% (95% confidence interval [CI], 76%-95%) and 81% (95% CI, 65%-91%), respectively. Twenty-seven patients (48%) showed a major response to PS with substantial improvement of cGVHD manifestations, including softening of the skin, increased range of motion, and improved performance status; 15 patients (27%) showed a minor response, defined as improvement in some but not all symptoms of cGVHD. Of the 42 responders, 21 (50%) had progression of their cGVHD afterwards. The median time to progression was 1.9 years. The probability of progression at 1 and 2 years after PS was 36% (95% CI, 23%-53%) and 54% (95% CI, 38%-71%), respectively. The probability of progression at 1 year was 25% (95% CI, 12%-47%) and 55% (95% CI, 32%-81%) for patients who had major and minor response, respectively (hazard ratio, 2.13). Ten of the 42 responders (24%) were able to discontinue all systemic immunosuppressive treatments. The probability of discontinuation at 1 and 2 years after PS was 9% (95% CI, 3%-25%) and 27% (95% CI, 15%-48%), respectively. The treatment was well tolerated with no serious adverse events. Our results suggest that PS is a well-tolerated regimen for achieving rapid clinical response in the majority of patients with cGVHD who failed on multiple previous therapies. Further studies are warranted to maintain the efficacy of this regimen by combining with new active agents in cGVHD.

Adolescent↗

PubMed2001

General pharmacology of IY-81149, a new proton pump inhibitor.

IY-81149 (2-[(4-methoxy-3-methyl)-2-pyridinyl]methylsulfinyl -5-(1H-pyrrol-1-yl)-1H-benzimidazole, CAS 172152-36-2) is a new proton pump inhibitor and expected to be an antiulcer drug. Its general pharmacological effects were studied in this paper. The doses given were vehicle control, 0.3, 1, 3, 100, 300 and 1000 mg/kg and were administered orally. The animals used in this study were mouse, rat, guinea pig and beagle dog. IY-81149 decreased spontaneous locomotor activity at 1000 mg/kg and showed a weak effect in motor performance at 300 and 1000 mg/kg. IY-81149 prolonged the hexobarbital-induced sleeping time dose dependently at 100, 300 and 1000 mg/kg. Oral administration of IY-81149 caused a dose-dependent hypothermic effect up to 300 mg/kg and showed analgesic effect at 1000 mg/kg. IY-81149 produced an antisecretory effect in pylorus ligated rats. The total gastric volume and acidity were significantly decreased at doses ranging from 1 to 3 mg/kg. However, IY-81149 had no effects on general behavior, did not show anticonvulsant activity, and did not affect blood pressure and heart rate, LVP (left ventricular peak systolic pressure), LVEDP (left ventricular end diastolic pressure), LVDP (left ventricular developing pressure), DP (double product), HR (heart rate), CFR (coronary flow rate), smooth muscle contraction, respiration, intestinal transport and renal function. These findings demonstrate that IY-81149 possesses weak central nervous system action and inhibitory effects on microsomal enzymes and gastric secretion after single administration. The results suggest that IY-81149 does not exert any notable pharmacological effects on the cardiovascular system, autonomic nerve system or smooth muscle function at all doses tested.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2001

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.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2001

Comparison of monocyte enrichment by immuno-magnetic depletion or adherence for the clinical-scale generation of DC.

BACKGROUND: DC generated from monocytes have been used for vaccines. We have developed a monocyte enrichment procedure by depleting T and B cells with anti-CD2 and anti-CD19 Abs using the automated Isolex 300i magnetic cell selector for clinical-scale DC generation in gas permeable SteriCell culture bags. We have also compared DC function, yield and purity of DC generated from adherent monocytes using culture bags in a closed system, with DC generated in conventional tissue culture flasks. METHODS: Monocytes were enriched from normal donor apheresis products using CD2/19 depletion with experimental software on the Isolex 300i (ISO), adherence (AD) to SteriCell bags and to T175 flasks and then cultured for 7 days in serum-free X-VIVO 15 media with GM-CSF and IL-4. Phenotype and dextran uptake were analyzed by flow cytometry and allogeneic MLR was also evaluated. RESULTS: ISO-DC and AD-DC from SteriCell bags showed similar viability. Higher purity of ISO-DC than AD-DC was measured by forward- and side-scatter flow cytometry. Similar expression of CD1a, CD80, CD86 and CD83 were observed in both ISO-DC and AD-DC. Similar dextran uptake and allo MLR were also observed. DISCUSSION: These data indicated that functional DC were generated in gas permeable SteriCell culture bags from both ISO- and AD-monocytes in a closed system.

Antigens, CD19↗

PubMed2001

Differential effects of autologous serum on CD34(+) or monocyte-derived dendritic cells.

Dendritic cells (DC) with potentially important clinical applications have been generated from human peripheral blood monocytes and CD34(+) cells in the presence of recombinant cytokines granulocyte-macrophage colony-stimulating factor (GM-CSF) + interleukin-4 (IL-4) and GM-CSF + tumor necrosis factor-alpha (TNF-alpha), respectively. Many of the studies generating DC have included fetal calf serum, which is not desirable due to the risk of immune reactions and infectious disease transmission. Additionally, low DC yields have been reported using serum-free media. In this study, we investigate supplementing serum-free media with autologous serum and plasma for DC generation from monocytes and CD34(+) cells. Our results show that functional DC can be reproducibly obtained in the presence of autologous serum using monocytes and CD34(+) cells as the starting populations. However, with the addition of autologous serum, a differential effect is observed in the phenotypic characterization of these culture-derived DC. Monocytes cultured for 7 days in X-VIVO 15 serum-free media in the presence of GM-CSF + IL-4 showed down-regulation of CD14 with increased expression of HLA-DR, mannose receptor, CD80, and CD86, along with highly up-regulated CD1a(+) expression. The addition of autologous serum to serum-free media in monocyte cultures resulted in a dose-dependent decrease in the CD1a(+) expression generating a distinct subset of CD1a(+/-) cells expressing HLA-DR, mannose receptor, CD80, and CD86. Upon stimulation with CD40L cells, both monocyte-derived DC subsets CD1a(+/-) and CD1a(++) were capable of maturation measured by CD83 and CD86 up-regulation. Data suggest the differences in the monocyte-derived DC in serum-free (CD1a(++)) or autologous serum (CD1a(+/-)) supplemented cultures is of a qualitative nature, rather than quantitative. CD1a(+) and CD14(+) cells expressing HLA-DR, mannose receptor, CD80, and CD86 were generated in 7 days from CD34(+) cells in serum-free media. A quantitative effect was obtained when cultures were supplemented with autologous serum, resulting in a significant enhancement of CD34-derived DC generated. These results demonstrate generation of DC from two different starting populations using serum-free media that can be enhanced with the addition of autologous serum. Interestingly, a differential effect was observed in the phenotypic characterization of these culture-derived DC.

Antigens, CD↗

PubMed2001

Maximal exercise as a countermeasure to orthostatic intolerance after spaceflight.

UNLABELLED: Previous investigators have suggested that maximal exercise performed 24 h before the end of bed rest, a spaceflight analog, restores prebed rest plasma volume, baroreflex responses, and orthostatic tolerance. PURPOSE: In this case report, we examined the effect of a similar exercise protocol 24 h before a Shuttle landing on the orthostatic responses of four crewmembers (EX) after spaceflights of 8-14 d. Four additional crewmembers (CON) served as controls and did not perform exercise during the final day of the flight. METHODS: Each crewmember performed a 10-min stand test approximately 10 d before launch (L-10) and within 1-2 h of landing (R+0). Cardiac stroke volume was measured (Doppler ultrasound) supine and during each min of standing for three EX and three CON subjects. RESULTS: Preflight, all crewmembers completed the stand test and each group had similar heart rate and blood pressure responses. Postflight, all subjects also completed the 10-min stand test. Each group had similarly elevated supine and standing heart rates, elevated diastolic and mean arterial blood pressures, and reduced pulse pressures compared to L-10. However, postflight cardiac output, mean +/- SEM, (EX: 4.5+/-0.6 L x min(-1); CON: 3.1+/-0.3 L x min(-1)) and stroke volume (EX: 43+/-7 mL x beat; CON: 30+/-6 mL x beat) were higher after 10 min standing in the EX subjects compared to CON subjects. CONCLUSIONS: For these four crewmembers, maximal exercise performed 24 h before landing may have helped maintain stroke volume but did not maintain heart rate and blood pressure responses during standing compared to preflight.

Adult↗

PubMed2001

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.

Allopurinol↗

PubMed2001

Combined phototherapeutic keratectomy and therapeutic contact lens for recurrent erosions in bullous keratopathy.

AIMS: To evaluate the therapeutic effects of excimer laser phototherapeutic keratectomy (PTK) combined with therapeutic contact lens for painful recurrent corneal erosions (RCE) secondary to bullous keratopathy (BK) not suitable for penetrating keratoplasty. METHODS: Excimer laser PTK was performed prospectively in eight eyes with painful RCE due to BK visually expecting no benefit from penetrating keratoplasty. After mechanical removal of the epithelium, the corneas were ablated with 50 pulses in the central 6.5 mm zone (ablation rate 0.25 microm per pulse) and another 200 pulses for polishing the periphery. After PTK, therapeutic contact lenses were applied for 3 months. The mean follow up period after PTK was 10.9 months (ranging from 6 to 15 months). RESULTS: All patients experienced relief of their pain symptoms after the epithelium healed. Only one patient complained of occasional stinging pain with intermittent recurrence of small bullae. He refused a second treatment because the pain was much less than that before the surgery and quite tolerable. No infection or other complications were noted. CONCLUSION: PTK with deeper ablation and adjunctive therapeutic contact lens is an easy to perform and effective treatment with less recurrence rate for patients with BK and poor visual potential.

Aged↗

PubMed2001

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.

Aged↗

PubMed2001

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.

Adult↗

PubMed2001

Thermovisual evaluation of acupuncture points.

The aim of our study is to evaluate the temperature distributions around the acupuncture points and channels by visualizing the infrared emissions emanated from the human skin. Our thermal imaging system that is the most sensitive to 10um long infrared wavelength allows us to recognize the actual location of acupuncture point and analyze its functional condition by examining the temperature gradient between the point and its surrounding skin area. The temperature perception of acupuncture point on extremities is especially important since its location and functional condition have a tendency to be altered if one contract disease such as immunodeficiency, arterial hypertension, and dyskinesia of biliary ducts. Also, thermovisual examinations over the acupuncture points allow us to perform the objective medical treatments by observing the transition of temperature gradients.

Acquired Immunodeficiency Syndrome↗

PubMed2001

Two processing methods for the isolation of Salmonella from naturally contaminated alfalfa seeds.

Two processing methods were examined for the recovery of Salmonella from naturally contaminated alfalfa seed. Seed samples, from each of three investigations, were processed by sprouting and shredding before preenrichment and culture. In lot A, Salmonella serotype Newport was isolated from 3 of 30 sample units with the sprouting method and 2 of 30 with the shredding method. In lot B, three serotypes in various combinations were isolated from 10 of 30 sample units with the sprouting method and 9 of 30 with the shredding method. In lot C, Salmonella group C1 was isolated from 27 of 30 sample units with the sprouting method and 24 of 30 with the shredding method. Additionally, serotype Newport was found in one lot C sample unit. Using shredded seed data, a most probable number (MPN) for Salmonella contamination per lot was calculated. Serotype Newport was estimated at 0.07 MPN/100 g in lot A; the concentration for three serotypes was estimated to be 0.36 MPN/100 g in lot B; Salmonella group C1 was estimated at 1.8 MPN/100 g in lot C. Our success in isolating Salmonella from alfalfa seeds was likely attributed to the volume of material tested and the quick acquisition of the seeds after the outbreak was identified. Shredding the seeds was easier and yielded definitive results more quickly than sprouting.

Disease Outbreaks↗

PubMed2001

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.

Base Sequence↗

PubMed2001

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.

Adult↗

PubMed2001

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.

Adult↗