The Arabidopsis thaliana SOS2 gene encodes a protein kinase that is required for salt tolerance

In Arabidopsis thaliana, the Salt Overly Sensitive 2 (SOS2) gene is required for intracellular Na(+) and K(+) homeostasis. Mutations in SOS2 cause Na(+) and K(+) imbalance and render plants more sensitive toward growth inhibition by high Na(+) and low K(+) environments. We isolated the SOS2 gene through positional cloning. SOS2 is predicted to encode a serine/threonine type protein kinase with an N-terminal catalytic domain similar to that of the yeast SNF1 kinase. Sequence analyses of sos2 mutant alleles reveal that both the N-terminal catalytic domain and the C-terminal regulatory domain of SOS2 are functionally essential. The steady-state level of SOS2 transcript is up-regulated by salt stress in the root. Autophosphorylation assays show that SOS2 is an active protein kinase. In the recessive sos2-5 allele, a conserved glycine residue in the kinase catalytic domain is changed to glutamate. This mutation abolishes SOS2 autophosphorylation, indicating that SOS2 protein kinase activity is required for salt tolerance.

SOS3 function in plant salt tolerance requires N-myristoylation and calcium binding

The salt tolerance gene SOS3 (for salt overly sensitive3) of Arabidopsis is predicted to encode a calcium binding protein with an N-myristoylation signature sequence. Here, we examine the myristoylation and calcium binding properties of SOS3 and their functional significance in plant tolerance to salt. Treatment of young Arabidopsis seedlings with the myristoylation inhibitor 2-hydroxymyristic acid caused the swelling of root tips, mimicking the phenotype of the salt-hypersensitive mutant sos3-1. In vitro translation assays with reticulocyte showed that the SOS3 protein was myristoylated. Targeted mutagenesis of the N-terminal glycine-2 to alanine prevented the myristoylation of SOS3. The functional significance of SOS3 myristoylation was examined by expressing the wild-type myristoylated SOS3 and the mutated nonmyristoylated SOS3 in the sos3-1 mutant. Expression of the myristoylated but not the nonmyristoylated SOS3 complemented the salt-hypersensitive phenotype of sos3-1 plants. No significant difference in membrane association was observed between the myristoylated and nonmyristoylated SOS3. Gel mobility shift and (45)Ca(2)+ overlay assays demonstrated that SOS3 is a unique calcium binding protein and that the sos3-1 mutation substantially reduced the capacity of SOS3 to bind calcium. The resulting mutant SOS3 protein was not able to interact with the SOS2 protein kinase and was less capable of activating it. Together, these results strongly suggest that both N-myristoylation and calcium binding are required for SOS3 function in plant salt tolerance.

Alterations of Fas (Apo-1/CD95) gene in non-small cell lung cancer

Fas (Apo-1/CD95) is a cell-surface receptor involved in cell death signaling. The key role of the Fas system in negative growth regulation has been studied mostly within the immune system, and somatic mutations of Fas gene in cancer patients have been described solely in lymphoid-lineage malignancies. However, many non-lymphoid tumor cells have been found to be resistant to Fas-mediated apoptosis, which suggests that Fas mutations, one of the possible mechanisms for Fas-resistance, may be involved in the pathogenesis of non-lymphoid malignancies as well. In this study, we have analysed the entire coding region and all splice sites of the Fas gene for the detection of the gene mutations in 65 human non-small cell lung cancers by polymerase chain reaction, single strand conformation polymorphism and DNA sequencing. Overall, five tumors (7.7%) were found to have the Fas mutations, which were all missense mutations. Four of the five mutations identified were located in the cytoplasmic region (death domain) known to be involved in the transduction of an apoptotic signal and one mutation was located in the transmembrane domain. This is the first report on the Fas gene mutations in non-lymphoid malignancies, and the data presented here suggests that alterations of the Fas gene might lead to the loss of its apoptotic function and contribute to the pathogenesis of some human lung cancers.

Dobutamine digital echocardiography for detecting coronary artery disease

To assess the value of dobutamine echocardiography for detecting coronary artery disease (CAD), 70 men (mean age 62 +/- 8 years) presenting for coronary angiography were prospectively studied. Dobutamine (2.5 to 40 micrograms/kg/min) was infused in 3-minute stages. Digital echocardiograms were recorded on-line at baseline, during low- and high-dose dobutamine infusion, and at recovery. An echocardiogram positive for CAD was defined as one showing a new wall motion abnormality induced by dobutamine. Compared with coronary angiography, the overall sensitivity of dobutamine echocardiography for detecting CAD was 86%, specificity 95% and accuracy 89%. The sensitivity for detecting 3-vessel CAD was 100%, 89% for 2-vessel and 69% for 1-vessel CAD. The accuracy of predicting multivessel disease by 2 methods was 71% and 84%, respectively. Heart rate at the echocardiographic ischemic threshold was lower in patients with 3- and 2-vessel CAD versus 1-vessel CAD (89 +/- 17, 95 +/- 18 and 118 +/- 18 beats/min, respectively, p less than 0.01); rate-pressure product was also lower in patients with 3- and 2-vessel CAD versus 1-vessel CAD (12.7 +/- 3.6, 13.7 +/- 2.8 and 18.9 +/- 44 x 10(3) beats/min x mm Hg, respectively, p less than 0.01). Heart rate was the most important physiologic determinant of ischemia induced by dobutamine. There were no major complications during the study. Thus, dobutamine digital echocardiography is an excellent test for identifying CAD and should be beneficial in patients unable to exercise.

Gender differences in autonomic cardiovascular regulation: spectral, hormonal, and hemodynamic indexes

The autonomic nervous system drives variability in heart rate, vascular tone, cardiac ejection, and arterial pressure, but gender differences in autonomic regulation of the latter three parameters are not well documented. In addition to mean values, we used spectral analysis to calculate variability in arterial pressure, heart rate (R-R interval, RRI), stroke volume, and total peripheral resistance (TPR) and measured circulating levels of catecholamines and pancreatic polypeptide in two groups of 25 +/- 1.2-yr-old, healthy men and healthy follicular-phase women (40 total subjects, 10 men and 10 women per group). Group 1 subjects were studied supine, before and after beta- and muscarinic autonomic blockades, administered singly and together on separate days of study. Group 2 subjects were studied supine and drug free with the additional measurement of skin perfusion. In the unblocked state, we found that circulating levels of epinephrine and total spectral power of stroke volume, TPR, and skin perfusion ranged from two to six times greater in men than in women. The difference (men > women) in spectral power of TPR was maintained after beta- and muscarinic blockades, suggesting that the greater oscillations of vascular resistance in men may be alpha-adrenergically mediated. Men exhibited muscarinic buffering of mean TPR whereas women exhibited beta-adrenergic buffering of mean TPR as well as TPR and heart rate oscillations. Women had a greater distribution of RRI power in the breathing frequency range and a less negative slope of ln RRI power vs. ln frequency, both indicators that parasympathetic stimuli were the dominant influence on women's heart rate variability. The results of our study suggest a predominance of sympathetic vascular regulation in men compared with a dominant parasympathetic influence on heart rate regulation in women.

Contribution of abnormal sarcoplasmic reticulum ATPase activity to systolic and diastolic dysfunction in human heart failure

Two of the most significant characteristics of failing human myocardium are an increased diastolic [Ca2+]i and a prolonged diastolic relaxation. These abnormalities are more pronounced at higher frequencies of stimulation and may be caused by an altered Ca2+ resequestration into the sarcoplasmic reticulum (SR). The force-frequency relationship was determined in multicellular preparations obtained from non-failing (n=6) and failing human myocardium (n=11). The active force in non-failing tissue increased as a function of the frequency of stimulation. In failing myocardium, an increase in frequency of stimulation (>1 Hz) was accompanied by a decrease in active force. Changes in the frequency of stimulation and active force were also associated with changes in intracellular calcium concentrations. The diastolic force in failing myocardium was augmented following an increase in frequency of stimulation, whereas in non-failing tissue, no increase in diastolic force was observed. Associated with the increase in diastolic force was an increase in intracellular diastolic calcium concentrations. The SR Ca2+ ATPase activity was reduced in failing compared to non-failing myocardium. SR Ca2+ ATPase was positively correlated with diastolic force in non-failing myocardium. The relationship between Ca2+ ATPase activity at 1 micromol/l [Ca2+] and active force between 0.5 and 2.0 Hz was different between failing and non-failing myocardium. The diastolic force demonstrate an inverse relationship with the SR Ca2+ ATPase activity in failing myocardium. These data suggest that a reduction in SR Ca2+ ATPase activity contributes to the impairment in both systolic and diastolic function of failing human hearts.

Measurement of total lung deposition of inhaled ultrafine particles in healthy men and women

Ultrafine particles (< 0.10 microm in diameter) are present in great number in polluted urban air, thus posing a potential health risk. In this study, the total deposition fraction (TDF) of ultrafine aerosols with a narrow size distribution (number median diameter NMD = 0.04-0.1 microm and geometric standard deviation sigma(g) = approximately 1.3) was measured in a group of young healthy adults (11 men and 11 women). TDF was obtained with 6 different breathing patterns: tidal volume (V(t)) of 500 ml at respiratory flow rates (Q) of 150 and 250 ml/s; V(t) = 750 ml at Q of 250 and 375 ml/s; and V(t) = 1 L at Q of 250 and 500 ml/s. Aerosols were monitored continuously by a modified condensation nuclei counter while subjects were inhaling them with prescribed breathing patterns. For a given breathing pattern, TDF increased as particle size decreased, regardless of the breathing pattern used. For example, with V(t) = 500 ml and Q = 250 ml/s, TDF (mean +/- SD) was 0.26 +/-.04, 0.30 +/-. 05, 0.35 +/-.05, and 0.44 +/-.07 for NMD = 0.10, 0.08, 0.06, and 0. 04 microm, respectively. For a given NMD, TDF increased with an increase in V(t) and a decrease in Q. TDF was greater for women than men at NMD = 0.04 microm within all breathing patterns used (p <.05), but the difference was smaller or negligible for larger sized particles. The results suggest that the TDF of ultrafine particles increases with a decrease of particle size and with breathing patterns of longer respiratory time, a pattern that is consistent with diffusion deposition of ultrafine particles. The results also suggest that there is a differential lung dose of ultrafine particles and thus there may be a differential health risk for men versus women.

Effects of chronic corticosteroids and vitamin A on the healing of intestinal anastomoses

The ability of vitamin A to reverse the inhibitory effects of chronic corticosteroids on cutaneous and fascial wound healing is well established. To investigate this in the unique low-collagen environment of the intestinal anastomosis, 35 rabbits received twice-daily injections of either saline (control), dexamethasone (0.1 mg/kg/day), dexamethasone plus low-dose vitamin A (1,000 IU/kg/day), or dexamethasone plus high-dose vitamin A (10,000 IU/kg/day) for a 2-week period. Animals then underwent creation of single-layer, inverting small and large intestine anastomoses. All injections were continued postoperatively. A fifth group received only dexamethasone preoperatively and dexamethasone plus high-dose vitamin A postoperatively. On postoperative day 7, animals underwent in situ assessment of anastomotic bursting pressure and subsequent histologic examination using a modified Ehrlich/Hunt scale. Corticosteroids significantly impaired the healing of small and large intestine anastomoses, with decreased bursting pressures and histologic parameters at 1 week. Only high-dose vitamin A significantly reversed this inhibitory effect, whether given preoperatively or only postoperatively.

Induction of apoptosis by diethylstilbestrol in hormone-insensitive prostate cancer cells

BACKGROUND

Diethylstillbestrol (DES) and diethylstilbestrol diphosphate (DESdP) are effective agents for the treatment of advanced prostate cancers. Tumor-inhibiting effects of DES and DESdP are presumed secondary to suppression of androgen production in vivo. Little is known, however, about the direct cellular mechanisms of the tumor inhibition. Estrogens have been reported not only to stimulate growth but also to disrupt microtubule formation in prostate cancer cells.

PURPOSE

The study was designed to examine and compare mechanisms of in vitro growth inhibition of DES and DESdP in human androgen-insensitive prostate cancer cells (DU145, 1-LN, and PC-3) and human androgen-sensitive prostate cancer cells (LNCaP) and to examine estrogen receptor modulation of such effects.

METHODS

The cytotoxic effects of DES and DESdP were examined in vitro by use of a standard microculture tetrazolium assay to quantitate numbers of viable cells. Immunofluorescence microscopy, DNA fragmentation analysis, and fluorescence flow cytometry were used to investigate microtubules, the induction of apoptosis, and changes in cell cycle distribution. The degree of estrogen receptor positivity of untreated and treated cells was determined by immunohistochemistry and quantitative image analysis.

RESULTS

LD50 levels (the dose at which 50% of cells are no longer viable) in the concentration range of 19-25 microM were observed for both DES and DESdP in all cell lines examined. DESdP-induced growth inhibition was found to be dependent on heat-labile phosphatases present in fetal calf serum. DES-induced cytotoxicity was not affected by the presence of 17 beta-estradiol, and it was not dependent on the presence of estrogen receptor. Estrogen receptor-positive cells and estrogen receptor-negative cells were equally responsive to DES. PC-3 cells stained with fluorescent anti-tubulin, phalloidin (actin stain), and 4',6-diamidino-2-phenylindole (DNA stain) showed no inhibition of microtubules or actin filaments but revealed the presence of apoptotic bodies in the nuclei. Fluorescence flow cytometry of nuclear DNA content of propidium iodide-stained nuclei from androgen-insensitive prostate cancer cells treated with 15 or 30 microM DES or DESdP revealed an increase in relative numbers of hypodiploid (apoptotic) nuclei, a depletion of G1- and S-phase cells, and an accumulation of cells in G2/M phase. Conversely, androgen-sensitive cells contained a lower percentage of hypodiploid nuclei but no accumulation of cells in G2/M phase.

CONCLUSIONS

Direct cytotoxic effects of DES in prostate cancer cells are estrogen receptor independent and do not involve disruption of microtubule architecture but do involve the promotion of cell cycle arrest and apoptosis. These are the first data confirming direct cytotoxic effects of DES and DESdP in prostate cancer cells via an apoptotic mechanism. IMPLICATIONS. These results suggest that DES and DESdP have potential value as agents against androgen-insensitive prostate neoplasms through induction of an apoptotic cascade.

Soluble beta-amyloid induction of Alzheimer's phenotype for human fibroblast K+ channels

Although beta-amyloid is the main constituent of neurite plaques and may play a role in the pathophysiology of Alzheimer's disease, mechanisms by which soluble beta-amyloid might produce early symptoms such as memory loss before diffuse plaque deposition have not been implicated. Treatment of fibroblasts with beta-amyloid (10 nM) induced the same potassium channel dysfunction previously shown to occur specifically in fibroblasts from patients with Alzheimer's disease--namely, the absence of a 113-picosiemen potassium channel. A tetraethylammonium-induced increase of intracellular concentrations of calcium, [Ca2+]i, a response that depends on functional 113-picosiemen potassium channels, was also eliminated or markedly reduced by 10 nM beta-amyloid. Increased [Ca2+]i induced by high concentrations of extracellular potassium and 166-picosiemen potassium channels were unaffected by 10 nM beta-amyloid. In Alzheimer's disease, then, beta-amyloid might alter potassium channels and thus impair neuronal function to produce symptoms such as memory loss by a means other than plaque formation.

Sensorineural hearing loss in otitis media

Additional evidence is presented to support the hypothesis that both acute purulent otitis media (POM) and chronic suppurative otitis media (COM) can cause high frequency sensorineural hearing loss. In selected patients and in animals (chinchillas) in a pilot study using electrophysiological methods, both temporary threshold shifts and permanent threshold shifts of basal cochlear turn involvement were demonstrated in POM. Data of cochlear involvement in 475 ears with bilateral COM, 607 ears with unilateral COM, and 607 ears serving as controls were obtained from six centers in five countries. In group 1 (15 dB or greater), 43% of ears with unilateral COM and 42% of ears with bilateral COM showed losses, for a combined odds ratio eight times that in controls. In group 2 (30 dB or greater), 16% of ears with unilateral COM and 17% of ears with bilateral COM demonstrated, respectively, seven and ten times that in controls. These statistically significant findings influence clinical considerations.

A simple and rapid method for isolation of high quality genomic DNA from fruit trees and conifers using PVP

Because DNA degradation is mediated by secondary plant products such as phenolic terpenoids, the isolation of high quality DNA from plants containing a high content of polyphenolics has been a difficult problem. We demonstrate an easy extraction process by modifying several existing ones. Using this process we have found it possible to isolate DNAs from four fruit trees, grape (Vitis spp.), apple (Malus spp.), pear (Pyrus spp.) and persimmon (Diospyros spp.) and four species of conifer, Pinus densiflora, Pinus koraiensis,Taxus cuspidata and Juniperus chinensis within a few hours. Compared with the existing method, we have isolated high quality intact DNAs (260/280 = 1.8-2.0) routinely yielding 250-500 ng/microl (total 7.5-15 microg DNA from four to five tissue discs).

GlideScope video laryngoscope: a randomized clinical trial in 203 paediatric patients

BACKGROUND

The GlideScope intubating device has been reported to provide a comparable or superior laryngoscopic view compared with direct laryngoscopy in adults. This study compared the use of the GlideScope with direct laryngoscopy for the laryngoscopic view and intubation time in children.

METHODS

The laryngoscopic view in 203 children was scored using both the Macintosh laryngoscope and the GlideScope using Cormack and Lehane (C&L) grades. After scoring each laryngoscopic view with and without BURP, the patients were randomly allocated to two groups. The trachea was intubated using direct laryngoscopy (Group DL, n=100) or the GlideScope (Group GS, n=103). We compared C&L grades for the two views in the same patient, and also the time to intubate for each group.

RESULTS

The GlideScope improved the view without BURP in the patients with C&L grade 2 (16/26, P<0.01) and with C&L grades 3 and 4 (7/11, P<0.05). The view with BURP was also improved by the GlideScope in C&L grade 2 (4/9, P<0.05) and with C&L grades 3 and 4 (4/5, P=0.059). The mean time for tracheal intubation was 36.0 (17.9) s in the GS group and 23.8 (13.9) s in the DL group (P<0.001).

CONCLUSIONS

In children, the GlideScope provided a laryngoscopic view equal to or better than that of direct laryngoscopy but required a longer time for intubation.

Regional deposition of inhaled particles in human lungs: comparison between men and women

We measured detailed regional deposition patterns of inhaled particles in healthy adult male (n = 11; 25 +/- 4 yr of age) and female (n = 11; 25 +/- 3 yr of age) subjects by means of a serial bolus aerosol delivery technique for monodisperse fine [particle diameter (Dp) = 1 micron] and coarse aerosols (Dp = 3 and 5 micron). The bolus aerosol (40 ml half-width) was delivered to a specific volumetric depth (Vp) of the lung ranging from 100 to 500 ml with a 50-ml increment, and local deposition fraction (LDF) was assessed for each of the 10 local volumetric regions. In all subjects, the deposition distribution pattern was very uneven with respect to Vp, showing characteristic unimodal curves with respect to particle size and flow rate. However, the unevenness was more pronounced in women. LDF tended to be greater in all regions of the lung in women than in men for Dp = 1 micron. For Dp = 3 and 5 micron, LDF showed a marked enhancement in the shallow region of Vp </= 200 ml in women compared with men (P < 0.05). LDF in women was comparable to or smaller than those of men in deep lung regions of Vp > 200 ml. Total lung deposition was comparable between men and women for fine particles but was consistently greater in women than men for coarse particles regardless of flow rates used: the difference ranged from 9 to 31% and was greater with higher flow rates (P < 0.05). The results indicate that 1) particle deposition characteristics differ between healthy men and women under controlled breathing conditions and 2) deposition in women is greater than that in men.

Rate of visual field loss and long-term visual outcome in primary open-angle glaucoma

PURPOSE

To evaluate long-term visual field outcome in primary open-angle glaucoma.

METHODS

In this retrospective cohort study, 40 eyes of 40 patients with primary open-angle glaucoma with elevated intraocular pressure and a minimum of 8-year longitudinal series of visual fields were plotted with Goldmann perimeter. Eyes with any other ocular disease except cataract were excluded. Manual grid templates were used to quantify the visual fields. Linear regression was performed to estimate the rate of visual field decline. Pertinent clinical factors were evaluated for statistical association with the rate of decline. Long-term clinical outcome including visual acuity, rate of legal blindness, and rate of medical and surgical interventions was also measured.

RESULTS

In the 40 eyes studied, with a mean follow-up of 14 years, the visual field score decreased at the rate of -1.5% per year. Overall, 68% showed significant decrease, and the rate of decrease among these eyes was -2.1% per year. Five eyes became legally blind from glaucoma; the cumulative rate of blindness from glaucoma was 19% at 22 years. Higher intraocular pressure and greater number of antiglaucoma medications on initial presentation were associated with faster and slower deterioration of visual field (compared with the average), respectively.

CONCLUSIONS

With standard glaucoma therapy, the rate of visual field loss in primary open-angle glaucoma is slow. Lower intraocular pressure and more antiglaucoma medications are associated with slower visual field decline. Legal blindness from glaucoma is 19% over a follow-up of 22 years.

Mucus clearance by two-phase gas-liquid flow mechanism: asymmetric periodic flow model

Mucus transport by two-phase gas-liquid flow mechanism was investigated with in vitro flow models under asymmetric periodic airflow conditions with nine different liquid solutions with rheological properties similar to human sputum. The flow model was made with 1.0-cm-ID glass tube and positioned either vertically or horizontally. With a constant supply of the test liquids into the model tube (0.5 ml/min), the liquid layer transport speed (LLTS) as well as the mean liquid layer thickness at steady-state condition (hs) was measured in conjunction with various airflow patterns of different expiratory and inspiratory flow rate, breathing frequency (f), and tidal volume (VT). The flow patterns were maintained within the range of normal breathing. In the horizontal tube model, LLTS ranged from 1.14 +/- 0.02 to 3.39 +/- 0.04 cm/min at the peak expiratory flow rate (VEp) of 30-60 l/min. The inspiratory flow rate, as well as f and VT did not affect LLTS. However, LLTS increased with increasing VEp, and at the same VEp LLTS was higher with viscoelastic than with viscous liquid. In the vertical tube model, the upward transport of mucus could not be achieved at VEp lower than 30 l/min particularly with low viscosity and low elasticity fluid. However, at high values of VEp, LLTS was comparable to that in the horizontal tube model with viscoelastic fluid, whereas LLTS of viscous liquid showed 26-40% lower than that in the horizontal tube model. The value of hs was 5-20% of the tube diameter at VEp of 30-60 l/min in both models. These results indicate that effective mucus clearance can be achieved by two-phase gas-liquid flow mechanism in patients with excessive bronchial secretions with biased tidal breathing favoring the expiratory flow and that the clearance can be further promoted by changing rheological properties of mucus.

Renal angiomyolipoma: selective arterial embolization--effectiveness and changes in angiomyogenic components in long-term follow-up

PURPOSE

To evaluate the efficacy of selective arterial embolization in symptomatic renal angiomyolipoma (AML) and the change in angiomyogenic components during long-term follow-up after embolization.

MATERIALS AND METHODS

Fourteen adult patients with symptomatic AMLs underwent 16 selective arterial embolizations. The embolic materials used were absolute alcohol with (n = 5) or without (n = 3) iodized oil, Gianturco coils (n = 4), and polyvinyl alcohol foam powder with gelatin sponge (n = 2). Follow-up ultrasonography and computed tomography (CT) were performed in six and 14 patients, respectively. The effectiveness of selective arterial embolization was evaluated on the basis of the area of the angiomyogenic components in the AML on initial and follow-up images and clinical improvement.

RESULTS

All patients showed devascularization of the tumor on the postembolization angiograms. In 13 patients, clinical symptoms disappeared. The follow-up period was 7-72 months (mean, 33 months). One patient underwent nephrectomy at 7 months after embolization because of a large cystic lesion found at 1 month. In long-term CT follow-up (> or =12 months) in 12 patients, nearly all angiomyogenic components disappeared, but fatty components partially shrank with liquefactive necrosis in tumors.

CONCLUSION

Selective arterial embolization is an effective and safe treatment of AML. The angiomyomatous components crucial for the prevention of bleeding were very sensitive to the embolization.

Comparative measurement of lung deposition of inhaled fine particles in normal subjects and patients with obstructive airway disease

Particulate pollutants have been suggested as a risk factor for increase in mortality and morbidity in patients with obstructive airway disease. In the present study we hypothesized that enhanced particle deposition dose is an underlying factor for such a finding. We measured lung deposition in normal healthy control subjects (N; n = 10) and in subjects with varying levels of airway obstruction: smokers (S; n = 10), smokers with small airways disease (SAD; n = 10), asthmatics (A; n = 5), and patients with chronic obstructive airway disease (COPD; n = 10). The subjects inhaled a uniform size sebacate aerosol (1-micron diameter) from a collapsible bag of a known volume (500 ml) repeatedly for as many as 15 breaths at a rate of 30 breaths/min. Aerosol concentration was monitored continuously at the mouth by a laser aerosol photometer. After correcting for particle loss in the bag, lung deposition fraction [DF = (inhaled minus exhaled)/inhaled], was determined breath by breath. DF values (mean +/- SD) were 0.14 +/- 0.02, 0.16 +/- 0.02, 0.21 +/- 0.05, 0.22 +/- 0.02 and 0.028 +/- 0.03 for N, S, SAD, A, and COPD, respectively. DF values in S, SAD, A, and COPD were 16, 49, 59, and 103% greater, respectively, than that of normal subjects (p < 0.05). DF of COPD was also greater than that of SAD or A (p < 0.05). No difference was found between SAD and A. When all of the subject data were combined, DF was correlated well with percent predicted FEV1 and FEF25-75 (r2 = 0.63 in both). The results indicate a marked increase in particle deposition in patients with obstructive lung disease, and this can be an important factor for the development of the adverse health effects of pollutant particles on the one hand and for the treatment of patients with drug aerosols on the other.

Lactulose production by �-galactosidase in permeabilized cells of Kluyveromyces lactis

Lactulose production from lactose and fructose was investigated with several commercial beta-galactosidases. The enzyme from Kluyveromyces lactis exhibited the highest lactulose productivity among the beta-galactosidases tested. The reaction conditions for lactulose production were optimized using cells that had been permeabilized by treatment with 50% (v/v) ethanol: cell concentration, 10.4 g l(-1); concentration of substrates, 40% (w/v) lactose and 20% (w/v) fructose; temperature, 60( degrees )C; pH 7.0. Under these conditions, the permeabilized cells produced approximately 20 g l(-1) lactulose in 3 h with a lactulose productivity of 6.8 g l(-1) h(-1). These results represent 1.3- and 2.1-fold increases in lactulose concentration and productivity compared with untreated washed cells. This is the first reported trial of enzymatic synthesis of lactulose using permeabilized yeast cells.

MR imaging-histopathologic correlation of radiofrequency thermal ablation lesion in a rabbit liver model: observation during acute and chronic stages

OBJECTIVE

To determine the ability of MR imaging to detect the pathological changes occurring in radiofrequency (RF) thermal lesions and to assess its accuracy in revealing the extent of tissue necrosis.

MATERIALS AND METHODS

Using an RF electrode, thermal lesions were created in the livers of 18 rabbits. The procedure involved three phases. In the acute phase, six animals were killed the day after performing thermal ablation with RF energy, and two on day 3. In the subacute and chronic phases, eight rabbits underwent percutaneous hepatic RF ablation. After performing MR imaging, two animals were sacrificed at 1, 2, 4, and 7 weeks after the procedure, and MR-pathologic correlation was performed.

RESULTS

In the acute phase, the thermal ablation lesions appeared at gross examination as well-circumscribed, necrotic areas, representing early change in the coagulative necrosis seen at microscopic examination. They were hypointense on T2-weighted images, and hyperintense on T1-weighted images. Gadolinium-enhanced MR imaging showed that a thin hyperemic rim surrounded the central coagulative necrosis. In the subacute phase, ablated lesions also showed extensive coagulative necrosis and marked inflammation at microscopic examination. Beyond two weeks, the lesions showed gradual resorption of the necrotic area, with a peripheral fibrovascular rim. The size of lesions measured by MR imaging correlated well with the findings at gross pathologic examination.

CONCLUSION

MR imaging effectively demonstrates the histopathological tissue change occurring after thermal ablation, and accurately determines the extent of the target area.

Evaluation of corrected flow time in oesophageal Doppler as a predictor of fluid responsiveness

BACKGROUND

Corrected flow time (FTc) by oesophageal Doppler is considered to be a 'static' preload index. We evaluated the ability of FTc to predict fluid responsiveness and compared this with the abilities of other preload indices, such as pulse pressure variation (PPV), central venous pressure (CVP), and left ventricular end-diastolic area index (LVEDAI).

METHODS

Twenty neurosurgical patients were studied. After induction of anaesthesia, FTc, PPV, LVEDAI, CVP, and stroke volume index (SVI) were measured before and 12 min after fluid loading with 6% hydroxyethyl starch solution (7 ml kg(-1)). Responders and non-responders were defined as those patients with an SVI increase >or= 10% or < 10% after fluid loading, respectively. Pearson's correlation was used to assess correlations between changes in SVI and initial haemodynamic variables. Receiver operating characteristic (ROC) curves were constructed and compared to evaluate the overall performance of preload indices (FTc, PPV, LVEDAI, and CVP) in terms of predicting fluid responsiveness.

RESULTS

FTc and PPV before fluid loading differed between responders (n = 11) and non-responders (n = 9), and correlated with changes in SVI (r = -0.515 and r = 0.696, respectively), which was opposite to that observed for CVP or LVEDAI. Areas under ROC curves for FTc [0.944 (SD 0.058)] and PPV [0.909 (0.069)] were significantly greater than those for CVP [0.540 (0.133), P < 0.001] and LVEDAI [0.495 (0.133), P < 0.001]. The optimal threshold value given by ROC analysis was 357 ms for FTc.

CONCLUSIONS

In this study, FTc predicted fluid responsiveness. However, FTc should be used in conjunction with other clinical information.

Pathology of chronic otitis media

A review of 800 pathological temporal bones collected from autopsy cases revealed 333 ((41.6%) to have some type of otitis media; purulent otitis media (52.5%), serous otitis media (6%), mucoid otitis media (4.5%), and chronic otitis media (36.9%). The 123 temporal bones with chronic otitis media were further studied and found to have granulation tissue, cholesteatoma, cholesterin granuloma, bone changes, and fibrosis. Other findings included tympanic membrane perforation, tympanosclerosis, metaplasia of the epithelium with subepithelial glandular formation, suppuration, labyrinthitis, and evidence of complications of chronic otitis media (meningitis, subdural abscess, brain abscess, petrositis, and endolymphatic hydrops). From this study it was concluded: 1) chronic otitis media occurred quite frequently, from a histological standpoint, in the absence of tympanic membrane perforation; 2) granulation tissue in temporal bones was found much more frequently in chronic otitis media than was cholesteatoma; and 3) complications and sequelae of otitis media tended to occur more commonly secondary to granulation tissue than to cholesteatoma.

Correlation between nasal obstruction symptoms and objective parameters of acoustic rhinometry and rhinomanometry

Acoustic rhinometry and rhinomanometry have been used to assess nasal airway patency objectively. We compared nasal obstruction symptoms before and after decongestion with several parameters of these objective tests. The patients assessed their nasal obstruction using a visual analogue scale (VAS). Cross-sectional areas and nasal resistance were measured by acoustic rhinometry and rhinomanometry before and after topical application of 1% phenylephrine solution in 32 patients with nasal obstruction symptoms. There was no significant correlation between the difference in the VAS and the difference in nasal resistance. There was also no significant correlation between the difference in the VAS and minimal cross-sectional area and cross-sectional areas at 3.3 cm (CA3.3), CA4.0 and CA6.4 from the nosepiece both in the wide and narrow sides and in both nasal cavities before and after nasal decongestion. It is concluded that rhinomanometry and acoustic rhinometry may have no diagnostic value in estimating the severity of nasal obstruction symptoms.

Assessment of regional deposition of inhaled particles in human lungs by serial bolus delivery method

Detailed regional deposition of inhaled particles was investigated in young adults (n = 11) by use of a serial bolus aerosol delivery technique. A small bolus (45 ml half-width) of monodisperse aerosols [1-, 3-, and 5-microns particle diameter (Dp)] was delivered sequentially to a specific volumetric depth of the lung (100-500 ml in 50-ml increments), while the subject inhaled clean air via a laser aerosol photometer (25-ml dead volume) with a constant flow rate (Q = 150, 250, and 500 ml/s) and exhaled with the same Q without a pause to the residual volume. Deposition efficiency (LDE) and deposition fraction in 10 local volumetric regions and total deposition fraction of the lung were obtained. LDE increased monotonically with increasing lung depth for all three Dp. LDE was greater with smaller Q values in all lung regions. Deposition was distributed fairly evenly throughout the lung regions with a tendency for an enhancement in the distal lung regions for Dp = 1 micron. Deposition distribution was highly uneven for Dp = 3 and 5 microns, and the region of the peak deposition shifted toward the proximal regions with increasing Dp. Surface dose was 1-5 times greater in the small airway regions and 2-17 times greater in the large airway regions than in the alveolar regions. The results suggest that local or regional enhancement of deposition occurs in healthy subjects and that the local enhancement can be an important factor in health risk assessment of inhaled particles.