Purification and characterization of the recombinant alginate lyase from Pseudomonas sp. leaked by Escherichia coli upon addition of glycine

The plasmid pAL205 encodes an alginate lyase gene of Pseudomonas sp. OS-ALG-9, fused in frame to the beta-galactosidase alpha-peptide gene. The alginate lyase (Aly) expressed in Escherichia coli (pAL205) was significantly secreted into the medium by the addition of glycine. The extracellular enzyme isolated from the culture of E. coli JM109 (pAL205) was purified over 15,000-fold by successive chromatography and subjected to amino acid sequence analysis. The sequence determined was identical to that of the intracellular protein. Since the activity and molecular size of the extracellular Aly is identical to the intracellular protein and to the Aly isolated from Pseudomonas, the glycine does not affect or modify the Aly during its leakage into the medium.

High gene expression in Escherichia coli of recombinant alginate lyase as a fused protein with beta-galactosidase alpha-peptide

Escherichia coli LE392 (pAL28) was previously isolated as a positive clone harboring the alginate lyase gene (aly) from an alginate-degrading strain, Pseudomonas sp. OS-ALG-9. The plasmid pAL205, one of the constructs obtained after successive subcloning of pAL28, gave the highest expression of aly in E. coli cells. A 8-fold increase in the alginate lyase (Aly) activity in E. coli JM109 (pAL205) was induced with isopropyl-beta-D-thiogalactoside, which was 210 times higher than that in E. coli LE392 (pAL28). The highly significant increase in the expression of the Aly enzyme with pAL205 was investigated through the nucleotide sequence around the 5' region of aly as well as the N-terminal sequence of the purified enzyme. It was found that the Aly expressed in E. coli (pAL205) was a fused protein containing 7 residues from the N-terminus of beta-galactosidase alpha-peptide and the mature protein found in the Pseudomonas sp. except for three residues in the N-terminal.

Reliability of the probability effect on event-related potentials during repeated testing

The reliability of event-related potentials (ERPs) was studied in 10 healthy adults who were tested 8 times over 7-10 day intervals using a standard auditory oddball paradigm. The difference waveforms, obtained by subtracting the averaged waveforms for frequent trials from those obtained in rare trials, were designed to analyze the components of the ERPs, such as the P300, and to focus on the reliability of the probability effect on the ERPs. The between-session reliability (8 sessions) and the within-session reliability (order of blocks or of different visual procedures) were computed for the obtained difference waveforms. The between-session reliabilities, expressed as the intraclass correlations (r') for the P300 amplitude, area and latency, were 0.70, 0.61 and 0.65, respectively. The within-session reliability, presented as the Pearson correlation coefficients (r) for the three P300 measures were 0.43, 0.35 and 0.25 for different eyes. The values were 0.45, 0.39, 0.42 between the first and the second blocks (eyes-open) and 0.58, 0.47 and 0.29 (eyes-closed). These findings indicate that the P300 amplitude calculated from the difference waveforms may be the most stable marker for the between-session reliabilities. There were no significant differences in the P300 measures over the 8 sessions, suggesting that habituation may not occur with the difference waveform reflecting the probability effect on ERPs. The difference waveform may be useful in research on repetitive group ERPs.

Dopamine-1 receptors in the proximal convoluted tubule of Dahl rats: defective coupling to adenylate cyclase

We have previously reported a defect in the coupling of the renal dopamine-1 receptor (D1) to adenylate cyclase (AC) in the proximal convoluted tubule (PCT) of the spontaneously hypertensive rat (Okamoto-Aoki strain). To determine if this defect is present in another model of hypertension, we microdissected PCTs from Dahl salt-sensitive (DSS) and Dahl salt-resistant (DSR) rats on low- or high-NaCl diet. The ability of two selective D1 agonists, fenoldopam and SND-919-C12, and forskolin to stimulate AC activity in PCT was determined in each of the four groups of rats. Fenoldopam (10(-7) M) and SND-919-C12 (10(-6) M) failed to stimulate AC activity in the PCT of DSS rats whether on a low- or high-NaCl diet. In DSR rats, however, both fenoldopam and SND-919-C12 stimulated AC activity by 289-320% and 220-270%, respectively, whether on a low- or high-NaCl intake. Forskolin (10(-5) M), which directly stimulates AC activity, increased AC activity in all four groups. These studies show that in DSS rats the D1 receptor in the PCT fails to respond to D1 agonists. This defect is not a consequence of the hypertension because it was present in the DSS rats on a low-salt diet and before blood pressure elevation.

Regulatory role of nucleotides in axonemal function

Axonemal sliding involves both sliding velocity and the extent of sliding, that is how many doublets slide. It is clear that axonemes cannot beat if all doublets were to slide simultaneously, thus sliding extent is important. Using the turbidimetric assay of sliding disintegration of Tetrahymena axonemes, we examined the sliding extent and th effect of APD, ATP, and ATP analogs on the sliding extent. Of course, ATP is necessary to produce sliding disintegration, but ATP alone did not produce extensive sliding disintegration. The additions of higher ATP concentration even in the presence of ADP inhibited sliding disintegration. We also observed sliding disintegration using ribose-modified ATP analogs, anthraniloylATP, and methylanthraniloylATP. The extent of sliding disintegration was proportional to the analog concentration. Thus in contrast to ATP, higher analog concentration was not inhibitory. These results indicate that high ATP concentration acts to inhibit the extent of sliding disintegration and that ADP relieves this inhibition. We propose a model in which the affinity of of multiple cooperative active sites are regulated by the binding of ATP or ADP to a regulatory site. This model provides a mechanism by which nucleotides regulate the extent of sliding necessary for effective axonemal bending.

Paroxysmal supraventricular tachycardia initiated by ventricular couplets in concealed ventricular trigeminy

A case report of a man with ventricular concealed trigeminy in whom ventricular couplets initiating paroxysmal supraventricular tachycardia were occasionally seen is reported. This is the first report on concealed trigeminy with couplets. This strengthens the authors' previous suggestion that supernormal conduction may occur in the reentrant pathway of extrasystoles, as a mechanism of ventricular couplets.

Study on pharmacological effect of bile salts, sodium scymnol sulfate, from Rhizoprionodon acutus. I. Effect of scymnol, chimaerol and sodium scymnol sulfate on cerebral anoxia

The effects of scymnol, chimaerol and sodium scymnol sulfate, prepared from the bile of Rhizoprionodon acutus, on cerebral anoxia were investigated in experimental models of hypoxia, ischemia and histotoxic anoxia in mice. Scymnol, at a dose of 100 mg/kg, showed a significant protective action against cerebral anoxia in all of the models studied and significantly increased the partial oxygen pressure of the arterial blood. The anti-anoxic activity of scymnol was found to be slightly greater than that of idevenone. A similar protective effect of sodium scymnol sulfate was seen at doses higher than 100 mg/kg. The survival time on hypoxia was significantly prolonged in the animals pretreated with chimaerol.

[Pathogenesis and treatment of accommodative disturbance]

Using a computer-assisted infrared optometer with a pupillograph, we tried to obtain basic understanding of accommodative disturbance and its by investigating tonic (dark focus) level of accommodation and quasi-static accommodative response. In normal volunteers in whom either visual fatigue, general fatigue, or drunkeness was loaded intentionally, myopic shift of refraction, increased refractive fluctuation, and miosis were induced in all cases but the effect on amplitude of accommodative response was minimal. Subjects that worked at a computer terminal all day for 2 years, but not controls, developed myopic change at a statistically significant level. The effect on tonic level of accommodation of subject age, sustained near-vision tasks, and topical application of autonomic-related drugs was investigated. In subjects with severe eyestrain, myopic shift of tonic accommodation and prominent pupillary unrest were observed, suggesting increased parasympathetic excitation. One patient who was accidentally exposed to diisopropyl fluorophosphate, a potent cholinesterase inhibitor, showed a phenomenon similar to that mentioned above. Chaos attractors based upon the Shil'nikov phenomenon were introduced for evaluation of microfluctuation and pupillary unrest, as first applied by Sumida et al. Topical application of low-dose cyclopentolate hydrochloride was effective for treating accommodative abnormality in professional computed workers, who sometimes develop abnormal parasympathetic excitation. Based on quasi-static accommodation measurements, accommodative abnormality after head and neck injury, including whiplash injury, was divided into two completely different states: accommodative spasm and palsy. Since quasi-static accommodation was greatly affected by satellite ganglion block, sympathetic innervation from cervical ganglions may strongly influence accommodative response. Hyperthyroidism, which may be accompanied by sympathetic hyper-excitation, showed diminished accommodative response. In patients after refractive surgery by excimer laser, there was no difference in accommodative response before and after surgery, although tonic accommodation was slightly unstable after surgery. These findings suggest that the evaluation of tonic level or a similar state of accommodation and pupillary unrest will yield extremely valuable information in regard to various accommodative disturbances.

Detection of human immunodeficiency virus, hepatitis B virus, and hepatitis C virus in donor eyes using polymerase chain reaction

Detection of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) in donor eyes was performed. DNAs were extracted from the uvea, and they were amplified using the polymerase chain reaction (PCR). Amplified viral DNAs were detected with liquid hybridisation and chemiluminescent assay in which no radioactive materials were used. This method was shown to have a sensitivity limit of fewer than 10 copies of HIV, making it much more sensitive than the current techniques employed in eye banks. The method was applied to 120 donor eyes, including four from donors seropositive for HBV. The HBV gene was detected in one case in which the donor's blood had not been tested for HBV. HIV and HCV genes were not detected in any of the samples. The assay could be an effective screening test for the detection of these viruses in eye bank eyes.

[The effect of stellate ganglion block on the local and global cardiac uptake of 123I-metaiodobenzylguanidine]

To investigate the effect of stellate ganglion block (SGB) on the cardiac uptake of 123I-metaiodobenzylguanidine (MIBG), four patients without heart disease underwent SGB. Studies were done twice: once with SGB and once without SGB. Anterior planar images and myocardial SPECT images were taken at 10 minutes and 60 minutes after MIBG injection both with and without SGB. Cardiac uptake of MIBG on planar images estimated by heart/liver ratio was significantly higher with SGB at both imaging times (p < 0.01, p < 0.05) than without SGB. SGB had no effect on the local uptake of MIBG on SPECT images. In conclusion, SGB did not change the local cardiac uptake of MIBG, but it appeared to increase the global myocardial uptake of MIBG.

Paracrine role of keratinocyte growth factor in rabbit corneal epithelial cell growth

Keratinocyte growth factor (KGF), a member of the fibroblast growth factor (FGF) family, is expressed in stromal fibroblasts and acts specifically on cells of epithelial origin as a paracrine mediator. In this study, we examined KGF and KGF receptor (KGF-R) mRNA expression in rabbit corneal epithelial cells and keratocytes, using a reverse transcription polymerase chain reaction (RT-PCR) method. We also examined the effects of KGF on the proliferation of rabbit corneal cells in vitro. mRNA from cultured rabbit skin fibroblasts, conjunctival fibroblasts, corneal epithelial cells and keratocytes was first reverse-transcribed, and then amplified by PCR using primers specific for KGF and KGF-R. KGF mRNA was expressed in skin fibroblasts, conjunctival fibroblasts and keratocytes, but not in corneal epithelial cells. In contrast, KGF receptor mRNA was expressed in corneal epithelial cells, but not in skin fibroblasts, conjunctival fibroblasts or keratocytes. The results of Southern hybridization experiments of PCR products also showed that KGF mRNA was expressed in skin fibroblasts, conjunctival fibroblasts and keratocytes, whereas KGF receptor mRNA was expressed in corneal epithelial cells. Nucleotide sequencing of the PCR products revealed that their sequences were identical to the expected nucleotide sequences. Using the methylene blue method, we found that KGF enhanced the growth of cultured rabbit corneal epithelial cells, but not keratocytes, at a concentration of 0.01 to 100 ng ml-1. Furthermore, KGF also augmented 3H-thymidine incorporation into the corneal epithelial cells. These results suggest that KGF is a paracrine mediator of the proliferation of corneal epithelial cells as well as of keratinocytes in the skin.

[Accommodative function in eyes exposed to diisopropyl fluorophosphate]

Using a computer-assisted infrared optometer we studied the long-term accommodative behavior in a 31-year-old man whose eyes had been accidentally exposed to diisopropyl fluorophosphate vapor. The initial examination revealed a delay of accommodative relaxation in both quasi-static and dynamic measurements, which recovered within one month, and a characteristic behavior in dark focus of accommodation, that is, a repetition of prominent myopic shift followed by rapid relaxation. This abnormal dark focus of accommodation appeared more marked after the subject was forced to fixate on a near target at a distance of three diopters. These abnormalities in dark focus of accommodation were fairly reduced three months later, but myopic shift was detected even 13 months later. The findings suggest a close association between myopic shift in the dark focus of accommodation and parasympathetic excitation.

Observations of human corneal epithelium by tandem scanning confocal microscope

We applied the tandem scanning confocal microscope (TSCM) to 30 healthy human corneas of 3 normal volunteers and 27 patients with cataract and retinal detachment to observe normal corneal epithelial cells in vivo. All corneas were normal under slit lamp microscopic examination. The superficial and basal epithelial cells close to the basal lamina in the central cornea were recorded on videotape and analyzed by a computer-assisted digitizer. The mean cell areas of superficial cells exposed at the surface and basal cells at the horizontal section were 624 +/- 109 microns2 and 66 +/- 5 microns2, respectively. The ratio of superficial to basal mean cell area was 11.0 +/- 4.5. TSCM was thus useful in evaluating the relationship between superficial and basal cells in human corneal epithelium in vivo.

[The accuracy and side effects of pharmacologic stress thallium myocardial scintigraphy with adenosine triphosphate disodium (ATP) infusion in the diagnosis of coronary artery disease]

The diagnostic accuracy and side effects of pharmacologic stress thallium myocardial scintigraphy with ATP infusion were studied in 172 patients with or without coronary artery disease. ATP was infused for five minutes at a rate of 0.16 mg/kg/min (group A) or 0.18 mg/kg/min (group B) via antecubital vein. One hundred and eleven (67 of group A, 44 of group B) of 172 patients underwent coronary arteriography (CAG). In 111 patients received CAG, overall sensitivity, specificity and accuracy of this method were 88%, 84% and 87%, respectively. In 67 patients of group A, these were 92%, 81% and 90%. In 44 patients of group B, 79%, 87% and 82% were documented (NS, between group A and B). Chest pain, flushing, bradycardia and ST depression were included in side effects caused by ATP infusion. At least one of these side effects were observed in 84% of the all 172 patients, 89% of group A and 75% of group B (NS). But, all of the side effects were spontaneously alleviated within two minutes without any therapy. In conclusion, pharmacologic stress myocardial scintigraphy with ATP infusion is very accurate and safe, and infusion rate of 0.16 mg/kg/min is optimal for this purpose.

Mechanism of bradycardia-dependent appearance of manifest extrasystoles in concealed ventricular trigeminy

A man with ventricular extrasystoles is described. To our knowledge, this is the first report of bradycardia dependent appearance of manifest extrasystoles in concealed trigeminy. The mechanism was satisfactorily explained, using the concepts of longitudinal dissociation and concealed 3:2 Wenckebach periodicity in the reentrant pathway of extrasystoles.

Immunohistochemical localization of transforming growth factor-beta 1, -beta 2, and -beta 3 latency-associated peptide in human cornea

PURPOSE

To study spatial distribution of TGF-beta isoforms (TGF-beta 1, -beta 2, and -beta 3) in the human cornea and to elucidate their biologic roles in corneal maintenance.

METHODS

Frozen sections obtained from eight human autopsy eyes were placed on gelatin-coated slides. After blocking of nonspecific binding sites, the slides were incubated with rabbit polyclonal antibody to the latency-associated peptide (LAP) region of human TGF-beta 1, TGF-beta 2, and TGF-beta 3 precursors, followed by the incubation with biotinylated swine anti-rabbit IgG. Subsequently, a streptavidin-labeled alkaline phosphatase technique was used.

RESULTS

In the corneal region, beta 1-LAP antibody did not stain either epithelium or stroma, beta 2-LAP antibody stained all epithelial cell layers and the corneal stroma, and beta 3-LAP antibody stained the subepithelial region alone. The staining pattern in the limbal region was almost the same as in the corneal region, except in the limbal stroma, which was stained with beta 1-LAP antibody in three of eight samples. In the trabecular meshwork, all samples showed clear staining with beta 2-LAP antibody, whereas beta 1-LAP and beta 2-LAP antibody stained faintly in five of eight and four of eight samples, respectively.

CONCLUSION

beta 2-LAP was found in the corneal epithelium and stroma and beta 3-LAP in the subepithelial region, suggesting that TGF-beta 2 and TGF-beta 3 may play essential roles in normal corneal epithelial maintenance in vivo.

[Measurement of pupillary unrest in subjects with nonspecific ophthalmic complaints]

Using a computer-assisted infrared optometer with a pupillometer, we studied pupillary unrest of 20 eyes of 20 patients suffering from nonspecific ophthalmic complaints, and of 20 eyes of 20 normal controls. The patient group had smaller mean pupil area than the control group (29 mm2 vs 38 mm2, p < 0.01), and showed prominent pupillary unrest and increased mean coefficient of variation (CV) of the pupil area (9.2% vs 3.4%, p < 0.001). Frequently, fairly long duration waves (longer than 1 sec) could be seen in the recordings of pupillary unrest in the patient group, but not in the control group. The patient group also showed significantly higher dark focus of accommodation than the control group (1.1 D vs 0.4 D, p < 0.01). These findings suggest that abnormal parasympathetic excitation may play a role in the etiology of continued nonspecific ophthalmic complaints.

[A new slit-lamp fluorophotometer for the clinical evaluation of corneal epithelial barrier function]

A new objective slit-lamp fluorophotometer was developed to examine corneal epithelial barrier function. This instrument has several new characteristics. The photodetector system is placed directly in front of the cornea and the focal diamond is accurately positioned at the corneal surface, permitting measurement of the barrier function of peripheral parts of the cornea. Due to the filter characteristics, measurement can be done even in a relatively bright room. Only one second is needed for measurement, eliminating blink interruption. Linear relationships were found between measurement count and fluorescein concentration. 0.5% and 3 microliters of fluorescein was applied to the eyes of healthy volunteers. In non-washed eyes, the concentration changes were consistent with tear turnover, and in washed eyes, the changes reflected the barrier function of the corneal epithelium and showed correlation with age. This instrument is also useful for determining autofluorescence. A significant relation was seen between autofluorescence and age.

Hot spots on liver scans associated with superior or inferior vena caval obstruction

Although hot spots on hepatic scintigrams have been reported in association with superior and inferior vena caval obstruction, these studies were not clinically correlated, and are hampered by the poor resolution of earlier scintillation cameras. In this report, a modern scintillation camera was used to study the formation of hot spots associated with superior and inferior vena caval obstruction. Moreover, radionuclide cavography was performed in 70 patients with superior vena caval (SVC) obstruction and in 95 patients with inferior vena caval (IVC) obstruction. As a result, 13 cases of hot spots in the liver were observed. In cases of SVC obstruction, hot spots were seen in the quadrate lobe, the medial segment, and the bare area of the liver. In IVC obstruction, a hot spot was seen in the quadrate lobe in all cases. In rare instances, in cases of both SVC and IVC obstruction, a hot spot was seen in the wide area. For these hot spots to develop, it appears necessary to have systemic-portal venous blood flow through the internal thoracic vein and the paraumbilical vein.

[Age-related alteration of tear dynamics in normal volunteers]

Age-related alteration of tear dynamics was studied using a newly developed fluorophotometer. The subjects, 55 eyes of 30 normal volunteers, included 32 eyes of 16 younger subjects in their twenties and 23 eyes of 14 older subjects aged 50 years and above. After instillation of 1 microliter of fluorescein solution at a concentration of 50 micrograms/ml into the temporal bulbar conjunctiva, fluorescence intensity was measured with the fluorophotometer every minute for 10 minutes after instillation. Fluorescein concentration was calculated from the intensity, and various parameters of tear dynamics were analyzed. In the younger subjects, the tear volume, initial turnover rate and basal turnover rate were 10.6 +/- 6.0 microliters, 37. 1 +/- 15.6%/min, and 25.8 +/- 15.2%/min, respectively. In the older subjects, these values were 6.5 +/- 2.6 microliters, 26.5 +/- 11.4%/min, and 20.5 +/- 13.5%/min, respectively. The basic tear flow rate, calculated from the basal turnover rate and tear volume, was 2.7 +/- 2.2 microliters/min in the younger and 1.4 +/- 1.0 microliter/min in the older subjects. There was a statistically significant difference in the tear volume, tear turnover rate, and basic tear flow rate between the younger and older subjects.

Demonstration of a marked reduction in the amount of GPIIb in most type II patients with Glanzmann's thrombasthenia

In this study employing a sensitive immunoblot assay, we have characterized GPIIb and GPIIIa in thrombasthenic platelets from seven type II and four type I patients from 10 unrelated families. The amounts of GPIIb and GPIIIa were both markedly reduced in all these patients, and abnormal molecular weight GPIIb or GPIIIa was not detected. In all of four type I patients the amount of GPIIb was much lower than that of GPIIIa. In this study, however, we found that the amount of GPIIb was also lower even in six out of seven type II patients. Immunodepletion of patients' platelets with AP2 (a monoclonal antibody specific for the GPIIb-IIIa complex), AP3 (specific for GPIIIa) or AMF7 (specific for alpha v) further confirmed that GPIIIa existed in excess, and demonstrated that excess GPIIIa were mostly in free form and not associated with GPIIb or alpha v. The reduction of GPIIb may represent an abnormality in GPIIb processing in these type II and type I thrombasthenic platelets. It remains unclear whether these two subgroups represent distinct categories.