The value of contrast echocardiography in the diagnosis of patent ductus arteriosus with Eisenmenger's syndrome

When patent ductus arteriosus (PDA) is complicated by pulmonary hypertension resulting in a right-to-left shunt, an erroneous diagnosis of primary pulmonary hypertension may be made, even after echocardiographic examination. Among the 8 patients referred to our echocardiography laboratory with the diagnosis of primary pulmonary hypertension between June 1994 and November 1999, 2 patients were found to have PDA with Eisenmenger's syndrome. Patent ductus arteriosus with Eisenmenger's syndrome can be diagnosed by the opacification of the abdominal aorta without opacification of the left-sided chambers during contrast echocardiography.

Studies on gelatin-based sponges. Part III: a comparative study of cross-linked gelatin/alginate, gelatin/hyaluronate and chitosan/hyaluronate sponges and their application as a wound dressing in full-thickness skin defect of rat

Novel cross-linked sponges composed of gelatin/alginate and gelatin/hyaluronate and chitosan/hyaluronate (GH, GA and CH, respectively) were prepared and compared. Six different sponges with or without silver sulfadiazine (AgSD) were applied on the full-thickness dorsal skin defect of Wistar rat. The histology and epidermal wound healing rates of the skin defects were investigated by light microscopy and computerized morphometry 5 and 12 days post-operatively. In our full-thickness wound model (diameter 1 cm), the AgSD-impregnated sponges showed good wound healing performances on the whole. However, there appeared meaningful differences of wound healing between the gelatin-based sponges (GH, GA) and the CH. GH with AgSD was found to show the best wound healing properties as a wound dressing resulting from histological findings and computerized morphometric analysis of epidermal healing.

Comparative effects of diltiazem with enflurane or desflurane on myocardial contractility and heart rate in the isolated rat hearts

BACKGROUND

The volatile anesthetics may reduce cardiac contractility by limiting both membrane Ca2+ entry and altering intracellular Ca2+ release. Additional pharmacological effects of calcium channel blockers could potentially enhance anesthetic-induced depression. The aim of this study was to compare the direct cardiac effects of enflurane and a new volatile anesthetic, desflurane, in combination with diltiazem on the isolated Sprague-Dawley rat heart.

METHODS

After stabilization period isolated rat hearts (n = 40) were perfused with an oxygenated modified Krebs' solution at 55 mmHg equilibrated with 1, 2 and 3 MAC of enflurane (1.7, 3.4 and 5.1 vol% respectively) or desflurane (6, 12 and 18 vol% respectively) in combination with 100 ng/mL diltiazem at 36 degrees C. Isovolumetric left ventricular pressure (LVP), rate of change of ventricular pressure (dp/dt), spontaneous heart rate and coronary flow were measured. To examine the indirect metabolic effect due to autoregulation of coronary flow, O2 delivery (DO2), myocardial O2 consumption (MVO2) and percent O2 extraction (POE) were also monitored.

RESULTS

Diltiazem plus enflurane or desflurane depressed LVP and dp/dt dose-dependently. Enflurane plus diltiazem significantly decreased heart rate more than desflurane plus diltiazem in a dose-dependent manner. Desflurane plus diltiazem significantly increased coronary flow more than enflurane plus diltiazem and oxygen delivery increased proportionally with coronary flow. But there were statistically insignificant dose-dependent increases in both groups. Myocardial oxygen consumption and percentage of oxygen extraction were also decreased dose-dependently in both groups. Bradydysrhythmia that accompanied atrioventricular dissociation occurred with diltiazem plus high enflurane or desflurane concentration at an incidence of 46% and 40% respectively.

CONCLUSIONS

These in vitro results demonstrate that diltiazem plus enflurane or desflurane depresses left ventricular contractile function and diltiazem plus enflurane causes higher incidence of bradydysrhythmia more than equivalent levels of diltiazem plus desflurane.

Differentiation between reversible and irreversible restrictive left ventricular filling patterns with the use of mitral annulus velocity

A restrictive left ventricular filling pattern is generally recognized as an ominous prognostic sign in patients with congestive heart failure. Recently, this filling pattern has been further categorized into reversible and irreversible groups according to the changes in the mitral inflow pattern after preload reduction; furthermore, the prognosis is reported to be different for the two groups. Forty-two patients with a restrictive left ventricular filling pattern who could adequately perform Valsalva's maneuver were studied. Baseline peak early (E) and late (A) mitral inflow velocities, E/A ratio, deceleration time of E velocity, peak early (E') and late (A') diastolic mitral annulus velocities, and E'/A' ratio were obtained. During Valsalva's maneuver, the E/A ratio reversed (<1) in fifteen patients (15/42, 36%). These patients were categorized as belonging to the reversible group. Among the baseline mitral inflow and mitral annulus velocity parameters, A' > 0.05 m/s best discriminated between the reversible and irreversible restrictive left ventricular filling patterns, with a sensitivity of 80% and a specificity of 85%.

Ammonia removal using hepatoma cells in mammalian cell cultures

It was examined whether hepatocyte cell lines can be used for ammonia removal in mammalian cell cultures. It was found that there exists a critical ammonium concentration level for each hepatocyte cell to remove ammonia. Among the cells tested in this work, primary hepatocytes showed the strongest ammonia removal capability if ammonium concentration is higher than the critical level. However, primary hepatocytes lost the liver function gradually and finally died after 2-3 weeks. Because of this limitation, primary hepatocytes were not appropriate to be used for ammonia removal in long-term cultures. Hep G2 cells, which are immortal, also showed a strong ammonia removal activity. The ammonia removal activity of Hep G2 cells depended on the concentration of ammonium in the medium, as in the case of primary hepatocytes. However, urea could not be detected in the course of ammonia removal by Hep G2 cells. Instead of urea, Hep G2 cells secreted glutamine into the culture medium. The capacity for ammonia removal was higher in the absence than in the presence of glutamine. Thus we checked the activity of glutamine synthetase in the Hep G2 cells. The level of glutamine synthetase activity increased with the addition of ammonium chloride. This result accounts for the ammonium concentration dependency of Hep G2 cells in ammonia removal and glutamine synthesis. Furthermore Hep G2 cells could grow well in the absence of glutamine, which was necessarily required in mammalian cell cultures. These results prove that glutamine formation serves as the primary mechanism of detoxifying ammonia in hepatocyte cell lines as expected. In addition, it was demonstrated that ammonium level could be reduced 38% and that erythropoietin production increased 2-fold in the mixed culture of Hep G2 and recombinant CHO cells.

Prosthetic ambulation in a paraplegic patient with a transfemoral amputation and radial nerve palsy

Great importance and caution should be placed on prosthetic fitting for a paraplegic patient with an anesthetic residual limb if functional ambulation is to be achieved. The combination of paraplegia with a transfemoral amputation and radial nerve palsy is a complex injury that makes the rehabilitation process difficult. This article describes a case of L2 paraplegia with a transfemoral amputation and radial nerve palsy on the right side. Following the rehabilitation course, the patient independently walked using a walker at indoor level with a transfemoral prosthesis with ischial containment socket, polycentric knee assembly, endoskeletal shank and multiaxis foot assembly and a knee ankle foot orthosis on the sound side. The difficulties of fitting a functional prosthesis to an insensate limb and the rehabilitation stages leading to functional ambulation are reviewed.

Regulation of CD27 expression in the course of germinal center B cell differentiation: the pivotal role of IL-10

The molecules of the TNF superfamily and their receptors play crucial roles in the humoral immune response. In view of the powerful effects on germinal center (GC) B cell differentiation, the expression of these molecules should be tightly regulated. In this study, we have undertaken a detailed analysis of the regulation of CD27 expression following the differentiation of GC B cells supported by a follicular dendritic cell line. We show that CD27 is differentially expressed on B cell subpopulations at different stages of differentiation. Naive B cells are virtually negative but plasma cells generated in vivo are strongly positive for CD27 expression. GC B cells that exhibit a moderate expression of CD27 remarkably up-regulate the expression levels of this molecule when they differentiate into plasma cells, which is induced by IL-10. The up-regulation of CD27 expression correlates with that of CD38. Therefore, high expression of CD27 molecules emerges as a specific marker for plasma cells. Our results suggest an important role for CD27 in the differentiation of GC B cells into plasma cells. Evaluation of CD27 expression levels may be of a clinical significance in assessment of B cell maturation in immunocompromised patients.

Endonasal endoscopic reduction of blowout fractures of the medial orbital wall

PURPOSE

This article describes the endonasal endoscopic reduction (EER) of blowout fractures (BOFs) of the medial orbital walls and reports the clinical results.

PATIENTS AND METHODS

Sixteen patients who underwent EER for a BOF of the medial orbital wall were analyzed. The surgical indications for treatment were diplopia, limitation of eye movements, and significant enophthalmos. They were followed-up for at least 3 months after the surgery. Surgical techniques, surgical results, and postoperative complications were reviewed.

RESULTS

There were no significant intraoperative or postoperative complications. Fourteen patients showed complete resolution of symptoms after the surgery. One patient, who had persistent diplopia and remaining enophthalmos, underwent medial wall reconstruction with a Medpor surgical implant (Porex Surgical Inc, College Park, GA) by a transorbital approach. Another patient, who had residual enophthalmos, had correction of enophthalmos after insertion of a Medpor implant. Both patients are now symptom-free.

CONCLUSION

The results indicate that EER is a safe and effective technique for the treatment of BOFs of the medial orbital wall.

Functional effects of TNF and lymphotoxin alpha1beta2 on FDC-like cells

Recent studies suggest that tumor necrosis factor (TNF) family members such as TNFalpha and lymphotoxin alphabeta (LTalpha1beta2) are important in the development of follicular dendritic cells (FDCs) and maintenance of FDC function. In this study we used FDC-like cells (FDC-LC) cultured from normal human tonsil and investigated the effects of TNF and LTalpha1beta2 on expression of adhesion molecules and the production of cytokines and chemokines. TNF and LTalpha1beta2 both increased the expression of VCAM-1 and ICAM-1 on FDC-LC. In addition, IL-4 with LTalpha1beta2 synergistically increased the expression of VCAM-1, but not ICAM-1. Cytokine IL-6 and IL-15 mRNAs were induced following stimulation with TNF and LTalpha1beta2. These two cytokines were present in FDC-LC supernatants by ELISA and increased following TNF and LTalpha1beta2 stimulation. We also examined FDC-LC for chemokines, which affect B cells, including IL-8, SDF-1, MIP3beta/ELC, and BCA-1/BLC. SDF-1 mRNA and protein were expressed by FDC-LC, and following stimulation with TNF and LTalpha1beta2, decreases in both were observed. Therefore, TNF and LTalpha1beta2, which are produced by activated B cells, increased the expression of adhesion molecules and cytokines from FDC-LC, potentially providing key signals to support germinal center B cell survival and differentiation.

Role of azaamino acid residue in beta-turn formation and stability in designed peptide

The structural perturbation induced by C(alpha)-->N(alpha) exchange in azaamino acid-containing peptides was predicted by ab initio calculation of the 6-31G* and 3-21G* levels. The global energy-minimum conformations for model compounds, For-azaXaa-NH2 (Xaa=Gly, Ala, Leu) appeared to be the beta-turn motif with a dihedral angle of phi= +/- 90 degrees, psi=0 degrees. This suggests that incorporation of the azaXaa residue into the i+2 position of designed peptides could stabilize the beta-turn structure. The model azaLeu-containing peptide, Boc-Phe-azaLeu-Ala-OMe, which is predicted to adopt a beta-turn conformation was designed and synthesized in order to experimentally elucidate the role of the azaamino acid residue. Its structural preference in organic solvents was investigated using 1H NMR, molecular modelling and IR spectroscopy. The temperature coefficients of amide protons, the characteristic NOE patterns, the restrained molecular dynamics simulation and IR spectroscopy defined the dihedral angles [ (phi i+1, psi i+1) (phi i+2, psi i+2)] of the Phe-azaLeu fragment in the model peptide, Boc-Phe-azaLeu-Ala-OMe, as [(-59 degrees, 127 degrees) (107 degrees, -4 degrees)]. This solution conformation supports a betaII-turn structural preference in azaLeu-containing peptides as predicted by the quantum chemical calculation. Therefore, intercalation of the azaamino acid residue into the i+2 position in synthetic peptides is expected to provide a stable beta-turn formation, and this could be utilized in the design of new peptidomimetics adopting a beta-turn scaffold.

Relationship between the extent of fracture and the degree of enophthalmos in isolated blowout fractures of the medial orbital wall

PURPOSE

This study investigated the relationship between the extent of fracture and enophthalmos in blowout fractures of the medial orbital wall.

PATIENTS AND METHODS

Nine patients with isolated blowout fractures of the medial orbital wall, confirmed by computed tomography scans, were evaluated. The area of fracture and the volume of herniated orbital tissue were determined from computed tomography scans using simple linear measurements. Each of the calculated values for area and volume were compared with the degree of enophthalmos to determine whether there was any significant relationship between them.

RESULTS

Enophthalmos increased proportionally as the area of fracture or the volume of herniated orbital tissue increased (P < .05). The area of fracture and the volume of herniated orbital tissue associated with 2 mm of enophthalmos were 1.9 cm2 and 0.9 mL, respectively, as calculated from the regression curve.

CONCLUSION

Enophthalmos of 2 mm or more, which is a frequent indication for surgery, can be expected when the area of fracture is 1.9 cm2 or more, or the volume of herniated orbital tissue is 0.9 mL or more.

Effects of different concentrations and volumes of formalin on pain response in rats

BACKGROUND

Formalin test is commonly used in animal model to assess injury-produced pain response. If the total amount of formaldehyde is fixed, its concentration and volume can be easily adjusted. We evaluated the effect of two sets of three solutions of formalin (one set of same dose of formaldehyde at different concentration and volume, i.e. 2.5%--100 microL, 5%--50 microL, 10%--25 microL, and another set of same volume but at different concentrations, i.e. 2.5%--100 microL, 5%--100 microL, and 10%--100 microL) on the injury-produced pain response in rat.

METHODS

Male Sprague-Dawley rats weighing 250-300 g were used. Following injection of formalin (n = 8 in each group) or saline (n = 6, control), the flinching frequencies and time spent in licking or biting the injected hind-paw in the early phase 1 (0-5 min after injection) and the late phase 2 (20-60 min after injection) were recorded. Sham-injection rats (n = 5) underwent subcutaneous insertion of the needle, but no substance was injected.

RESULTS

Flinching in phase 1 and 2 was more frequent in the 2.5%--100 microL and 5%--50 microL groups than in the control group (P < 0.05). Licking (or biting) time in phase 2 in all these three groups was longer than the control group (P < 0.05). In the groups of another set of three different solutions (2.5%--100 microL, 5%--100 microL, and 10%--100 microL), flinching in phase 1 and phase 2 was also more frequent than the control group (P < 0.05). Regarding lick behavior of another set, it occurred more frequently in 2.5%--100 microL group in phase 1 and in 2.5%--100 microL group as well as 5%--100 microL group in phase 2 than the control group (P < 0.05).

CONCLUSIONS

The 10%--25 microL formalin produces fewer flinching responses than other concentrations. Flinching was a biphasic behavior which was more spontaneous and active than was licking. The volume of formalin was a more important factor than the concentration of formalin in the generation of the active biphasic flinching response in the rat model.

Upregulation of phospholipase D in astrocytes in response to transient forebrain ischemia

Previous in vitro studies using cell cultures or brain slices have demonstrated that phospholipase D (PLD) in the nervous system is involved in the signaling mechanism in response to a variety of agonists. However, little is known about the pathophysiological role of PLD-mediated signaling in the adult brain. We examined the changes in the expression of a PLD isozyme, PLD1, in the adult rat hippocampus, using immunological approaches and an assay for PLD activity after transient forebrain ischemia (four-vessel occlusion model) that results in the selective delayed death of CA1 pyramidal cells and induces reactive astrocytes in the CA1 subfield. In the control hippocampus, PLD1 the level of immunoreactivity was very low. After ischemia, in parallel with the results of Western blot analysis and the PLD activity assay, immunohistochemical analysis of PLD1 demonstrated that the immunoreactive proteins peaked at 7-14 days and were most prominent in the CA1 and the dentate hilar region. The temporal and spatial patterns of immunoreactivity of both PLD1 and glial fibrillary acidic protein (GFAP) were very similar, indicating that reactive astrocytes express PLD1, confirmed by double staining for PLD1 and GFAP. These results demonstrate that reactive astrocytes upregulate PLD in vivo after injury in the adult rat hippocampus.

Synergistic effect of angiotensin-converting enzyme and angiotensinogen gene on cardiac hypertrophy

AIMS

There are controversies concerning the association of angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism with left ventricular hypertrophy (LVH), and the unclear association between angiotensinogen (ATG) M235T polymorphism and LVH. We investigated both the separate and interactive effects of these two genes on LVH in patients (N=396) with cardiovascular disease and normal healthy volunteers (N=133).

RESULTS

Frequency of DD genotype of ACE gene was significantly (P<0.05) higher in patients with LVH than patients without LVH or normal controls. Frequency of IT genotype of ATG gene in patients with LVH was significantly (P<0.01) greater than that in normal controls or marginally (P=0.1) higher than that in patients without LVH. These findings were also observed in normotensive patients and normal controls after excluding hypertensive patients. Only in patient group, the frequency of DD genotype in the highest quartile of LVMI was significantly greater than that in the lowest quartile (P<0.05). The higher tendency of TT genotype in the highest quartile patients compared with that in the lowest, did not reach statistical significance. In combined genotype analysis, there was a remarkable difference in LVMI between the two extreme double homozygotes only in patient group (156+/-25 versus 109+/-25 g/m2 for TT+DD versus MM+II) (P<0.01). In ANCOVA, the interaction term composed of ACE and ATG genotype was a significant independent variable for LVMI only in the male patient group (P<0.01).

CONCLUSION

The D-allele of ACE and T-allele of ATG gene exert a synergistic effect on cardiac hypertrophy in male patients with cardiovascular diseases, but not in normal healthy population.

Distinct role of follicular dendritic cells and T cells in the proliferation, differentiation, and apoptosis of a centroblast cell line, L3055

Germinal center (GC) B cells undergo complex interactions with follicular dendritic cells (FDC) and T cells in the course of differentiation into memory B and plasma cells. To delineate the individual roles of FDC and T cells at each stage of GC B cell differentiation at the clonal level and to analyze the signals involved, we adopted a unique experimental model using an FDC line, HK, and a lymphoma cell line, L3055, that resembles centroblasts. A detailed phenotypic analysis revealed L3055 cells to be a clonal population originating from the GC. Like freshly isolated centroblasts, L3055 cells underwent spontaneous apoptosis when cultured in the absence of fresh FDC or HK cells. L3055 cells proliferated continuously in the presence of HK cells, while they differentiated into a population with the phenotype of centrocytes after stimulation with CD40 ligand (CD40L) and IL-4. The CD40L-stimulated L3055 cells underwent CD95-mediated apoptosis, which was reminiscent of the feature of CD40L-stimulated tonsillar GC B cells. In contrast to HK cells that did not protect L3055 cells from anti-Ig killing, CD40L plus IL-2, IL-4, and IL-10 prevented anti-Ig-induced apoptosis. These experimental results demonstrate a distinct function of FDC and activated T cells, in that FDC provide signals for rapid proliferation of centroblasts, whereas T cells confer signals for differentiation of centroblasts into centrocytes and resistance to B cell receptor-mediated apoptosis. T cells collaborate with FDC in the protection and expansion of the Ag-specific GC B cells.

Progenitor cell cycling during hair cell regeneration in the vestibular and auditory epithelia of the chick

We investigated nucleotide-labeling patterns during ongoing hair cell regeneration in the avian vestibular epithelium and during drug-induced regeneration in the avian auditory epithelium. For utricle experiments, post-hatch chicks received an injection of bromodeoxyuridine (BrdU) and were allowed to survive from 2 hours to 110 days after the injection. Utricles were fixed and immunoreacted to detect BrdU. The number of BrdU-labeled nuclei in the hair cell and support cell layers of the utricular sensory epithelium changes significantly between 2 hours and 110 days post-BrdU. At 2 hours, most labeled cells are isolated, while by 5-10 days, the majority of labeled cells are organized in pairs that are most frequently composed of a hair cell and a support cell. Pairs of labeled cells are seen as late as 110 days. Clusters of more than 3 labeled cells are uncommon at all time-points. The total number of labeled cells increases approximately 1.5-fold between 5 and 60 days post-BrdU. This increase is due primarily to a rise in the number of labeled support cells, and it is likely that it represents additional rounds of division by a subset of cells that were labeled at the time of the BrdU injection. There is a significant decrease in labeled nuclei in the hair cell layer between 60 and 110 days post-BrdU, suggesting that hair cells die during this period. To investigate support cell recycling in the drug-damaged auditory epithelium, we examined nucleotide double labeling after separate injections of BrdU and tritiated thymidine. A small number of support cells that incorporate BrdU administered at 3 days post-gentamicin treatment also label with tritiated thymidine administered between 17 and 38 hours later. We conclude that a small population of support cells recycles during regeneration in both the normal utricle and the drug-damaged basilar papilla.

Studies on gelatin-containing artificial skin: II. Preparation and characterization of cross-linked gelatin-hyaluronate sponge

This study was conducted to develop a new sponge type of biomaterial to be used for either wound dressing or scaffold for tissue engineering. We were able to prepare an insoluble matrix composed of gelatin and sodium hyaluronate (HA) by dipping the soluble sponge into 90% (w/v) acetone/water mixture containing a small amount of cross-linking agent, 1-ethyl-3-3-dimethylaminoproplycarbodiimide hydrochloride, EDC. To characterize the sponge, Fourier-transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and Instron analysis were performed. The obtained results indicate that the chemically cross-linked sponge shows a cross-linking degree of 10-35%, a mean pore size of 40-160 microm, porosity of 35-67%, and a tensile strength of 10-30 gf/cm(2). Especially, the porosity measured by image analysis showed a tendency to increase with HA content, resulting in an increased water uptake. The resistance to collagenase degradation in vitro increased for up to 2 days. Silver sulfadiazine (AgSD)-impregnated gelatin-HA sponge was also prepared and compared with conventional vaseline gauze by applying it onto a dorsal skin defect of wistar rat for 5, 12, and 21 days. Histological results showed an enhancement of wound healing in AgSD-impregnated gelatin-HA sponge.

Heart failure in Korean elderly patients — clinical features, prognosis and prognostic factors

Heart failure (HF) is very common in the elderly but there are not sufficient data about the clinical characteristics and prognostic factors of HF among the Asian elderly patients. The aim of the study was to find out the clinical characteristics, survival, and prognostic factors of HF in Korean elderly patients. Among elderly patients admitted from February 1995 to February 1998, the patients with a discharge diagnosis of HF were enrolled. Through the medical record review, the diagnosis was confirmed and clinical parameters to affect survival were identified. Total number of the subjects was 104 [age: 77+/-7 years (65-96), male:female=36:68, follow-up duration: 20+/-14 months, LVEF: 46+/-16%]. Ischemic heart disease (IHD) was the most common cause of HF (42%) followed by valvular heart disease (28%), and hypertension (20%). The 1-year survival rate was 71.3%. Advanced age [risk ratio (RR): 1.41 per 5 years of age; 95% CI: 1.11-1.80] and reduced left ventricular ejection fraction (0.69 per 10%, 0.52-0.93), poor initial functional class (2.40, 1.15-5.00), diabetes (2.79, 1.30-5.97) and past history of HF (2.37, 1.10-5.10) badly affected the survival rates. When the Cox proportional hazard model was applied for multivariate analysis, only aging (1.64 per 5 years of age, 1.19-2.28) and diabetes (4.92, 1.83-13.23) predicted poor prognosis. Twenty-seven percent of the patients had diastolic HF (LVEF>45%, LVEDD<55 mm) who had higher survival rates with marginal significance (0.35, 0.10-1.17, P=0.09).

Transient upregulation of osteopontin mRNA in hippocampus and striatum following global forebrain ischemia in rats

We investigated the spatial and temporal expression of osteopontin (OPN) mRNA following transient forebrain ischemia in rats. Experiments were carried out using a four-vessel occlusion model for forebrain ischemia. The transient induction of OPN mRNA after global ischemia occurred earlier in the striatum than in the hippocampus. It was pronounced in the dorsomedial striatum close to the lateral ventricle and in the CA1 subfield and the subiculum of the hippocampus before microglial cells became more reactive. It also could be detected in the dentate hilus and to a marginal extent in the CA3. Our results suggest that the hippocampus and the striatum following global forebrain ischemia upregulate OPN mRNA in different spatiotemporal profiles.

Solution conformation on bovine growth hormone releasing factor by 1H NMR and molecular modeling

The structure of bovine growth hormone releasing factor (bGHRF) consisting of 44 amino acids has been studied in CD and 1H nuclear magnetic resonance (NMR) spectroscopy in conjunction with molecular modeling. Since bGHRF does not have an ordered structure in water alone, a 30% 2,2,2-trifluoroethanol (TFE) aqueous solvent was used to induce considerable alpha-helical structures, which corresponds to a helical content of approximately 62% as determined by circular dichroism (CD). The secondary structure was obtained from nuclear Overhauser enhancement and 3J(HN alpha) coupling constant in 30% TFE solution. Three-dimensional structures consistent with NMR data were generated by using distance geometry calculation. A set of 267 interproton distances derived from nuclear Overhauser effect correlation spectroscopy (NOESY) experiments and coupling constants were used. From the initial random conformations, 50 distance geometry structures with minimal violations were selected for further refinement. The 14 best structures were obtained after simulated annealing calculation with energy minimization. The structure of bGHRF in 30% TFE solution was characterized by one alpha-helix (residues 8-19), two poorly constrained helices (residues 23-27 and residues 31-34) and a beta I(III)-turn fragment (residues 20-23; phi(i+1) = -53.1 degrees, psi(i+1) = -19.6 degrees, phi(i+2) = -59.9 degrees, psi(i+2) = -20.6 degrees) connected by the segments of less defined structures in N-terminal and omega-shaped flexible C-terminal determined from NOESY cross peaks between helical segment (residues 14-18) and tail fragment (residues 42-44). The obtained structure will play an important role toward the understanding of the structural and functional role of the GHRF.

Study of user preference of graphic user interface in laboratory information system

In order to elucidate employees satisfaction levels in using graphic user interface. (GUI) in a laboratory information system (LIS), users attitudes toward GUI versus CUI. (Character User Interface) in a similar LIS were surveyed one month after implementing upgraded version of LIS in a tertiary care university hospital laboratory. The outcome of the study showed that approximately two third of users preferred to have GUI in LIS. There was no difference in preference of GUI of users whether they had previous experience with GUI or not. However the female and older employees tend to shy away from GUI. The employee productivity was improved with GUI although it takes slightly longer program loading time than that of CUI. In conclusion, the laboratory employee satisfaction was higher with GUI than CUI and their productivity was improved with GUI.

Variant angina is not associated with angiotensin I converting enzyme gene polymorphism but rather with smoking

BACKGROUND

Angiotensin converting enzyme (ACE) perhaps plays roles in regulating coronary vasomotor tone by producing angiotensin II and degrading bradykinin.

OBJECTIVES

We sought to investigate the role of ACE gene polymorphism in the pathogenesis of variant angina and to compare it with that of other clinical risk factors for male patients with variant angina and age-matched and sex-matched control subjects.

METHODS

We studied 78 male patients with variant angina who exhibited spontaneous or provoked coronary spasms during coronary angiography and compared prevalences of ACE gene genotype (deletion D and insertion I) and other risk factors between this group of patients with variant angina and age-matched and sex-matched control subjects whose angiograms were normal and in whom the ergonovine test did not cause spasms (n = 80).

RESULTS

Smokers were more prevalent in the group of patients with variant angina (P < 0.05). Genotype and allele prevalences of the group of patients with variant angina (0.14, 0.53 and 0.33 for DD, DI and II and 0.41 and 0.59 for D and I, respectively) were no different from those of the control group (0.16, 0.49 and 0.35 for DD, DI and II and 0.40 and 0.60 for D and I). Multiple logistic regression analysis showed that smoking was a significant risk factor for variant angina (odds ratio 2.61, 95% confidence interval 1.03-6.66) whereas ACE genotype was not.

CONCLUSIONS

Variant angina is associated with an environmental factor, such as smoking, rather than a genetic factor, such as ACE gene polymorphism.

Study on gelatin-containing artificial skin: I. Preparation and characteristics of novel gelatin-alginate sponge

An absorbable sponge, composed of gelatin and alginate, was prepared by new crosslinking method that improved the efficiency of crosslinking. The crosslinking degree was characterized by trinitrobenzenesulfonic acid (TNBS) assay. A water uptake ability test, in vitro drug release and collagenase degradation tests, and an in vivo animal test were employed to confirm the applicability of this gelatin-alginate sponge as a wound dressing material. As the alginate content in the sponge increased, the porosity increased, resulting in an enhanced water uptake ability. Sponges loaded with silver sulfadiazine or gentamicin sulfate slowly released drugs for up to four days. The crosslinked sponge resisted in vitro collagenase digestion for up to three days. An in vivo animal test using witar rat showed rather good wound healing effect of gelatin-alginate sponge containing AgSD than vaseline gauze in our full-thickness skin defect model.

Evaluation of left ventricular diastolic function when mitral E and A waves are completely fused: role of assessing mitral annulus velocity

Mitral inflow parameters have been used most widely in the evaluation of left ventricular (LV) diastolic function. However, when the mitral E and A waves are completely fused, mitral inflow parameters cannot provide information about the LV diastolic function. LV filling pressure, mitral inflow, mitral annulus velocity, and tau (tau) were measured in 59 patients with sinus rhythm when mitral E and A waves were completely fused with right atrial pacing. When mitral E and A waves were completely fused, tau correlated with the peak fused mitral annulus velocity (r = -0.60, P <.001), and peak fused mitral annulus velocity of less than 12.5 cm/s best discriminated prolonged (>/=50 ms) from normal tau, with a sensitivity of 78% and specificity of 69%. The peak fused mitral inflow velocity to peak fused mitral annulus velocity ratio correlated with LV filling pressure (r = 0.62, P <.001). A ratio of at least 8, could predict elevated LV filling pressure (>/=15 mm Hg) with a sensitivity of 65% and specificity of 74%. In conclusion, even when mitral E and A waves are completely fused, mitral annulus velocity can be used in the evaluation of LV diastolic function.