[Assessment of coronary stenosis severity using a Doppler guide wire in vivo: is the continuity equation applicable to moderate to severe coronary artery stenosis?]

The usefulness of a Doppler guide wire was evaluated in the estimation of coronary stenosis severity in patients with moderate to severe coronary stenosis using the continuity equation. The maximal coronary flow velocities (V) proximal to the stenosis (p), at the stenosis (s), and distal to the stenosis (d) were measured using a Doppler guide wire (12-MHz, 0.018-in) in 12 patients with mild coronary stenosis (less than 50% diameter stenosis: group A) and 12 patients with moderate to severe coronary stenosis (more than 50% diameter stenosis: group B). Percent diameter stenosis (%DS) was calculated from Vp/Vs by: %DS = (1 - square root of Vp/Vs) x 100 (%) (Vp = the maximal velocity proximal to the stenosis; Vs = the peak velocity at the stenotic site) Percent DS was calculated from Vd/Vs by: %DS = (1 - square root of Vd/Vs) x 100 (%) (Vd = the peak velocity distal to the stenosis) Regression of Doppler-derived %DS from Vp/Vs compared to quantitative coronary angiographic % DS were: Group A: y = 0.83x + 3.0 (r = 0.79), Group B: y = 0.63x + 9.4 (r = 0.81), Overall: y = 0.63x + 9.6 (r = 0.91) Regression of Doppler-derived %DS from Vd/Vs compared to quantitative coronary angiographic %DS were: Group A: y = 0.98x - 1.0 (r = 0.81), Group B: y = 0.67x + 14.6 (r = 0.84), Overall: y = 0.79x + 7.6 (r = 0.91) The continuity equation method using a Doppler guide wire underestimates coronary stenosis severity in patients with moderate to severe coronary stenosis, although Doppler-derived %DS is correlated with angiographic %DS.

[Pulsed Doppler findings of the pulmonary vein flow in mitral stenosis]

Left atrial function was assessed by transesophageal echocardiography in 8 patients with mitral stenosis and sinus rhythm (MS group), and 16 age-matched normal controls (C group). Pulsed Doppler findings of left upper pulmonary vein flow were classified into first and second forward waves during systole (S1, S2), forward wave during diastole (D), and backward flow during left atrial contraction (PVA). Peak velocity (P) and time-velocity integral (TVI) of each wave and acceleration and deceleration slope of S2 wave (S2-Ac, S2-Dc) were obtained. TVI-S2 and P-D in the MS group were significantly lower than those in the C group (TVI-S2: 4 +/- 2 vs 12 +/- 3 cm, P-D: 27 +/- 13 vs 41 +/- 12 cm/sec). S2-Ac and S2-Dc in the MS group were significantly higher than those in the C group (S2-Ac: 456 +/- 116 vs 323 +/- 118 cm/sec2, S2-Dc: 380 +/- 102 vs 165 +/- 48- cm/sec2). There were no differences in S1 and PVA. Lower TVI-S2 in the MS group suggests decreased reservoir function of the left atrium. Lower TVI-S2 in the MS group was caused by increased S2-Ac and S2-Dc which suggests increased left atrial preload and deterioration of left atrial compliance. Decreased P-D in the MS group reflects dysfunction of mitral valve opening.

Synthesis and pharmacological activities of novel bicyclic thiazoline derivatives as hepatoprotective agents. I. 8-Ethoxycarbonyl-5,6-dihydrothiazolo[2,3-c][1,4]thiazine derivatives

A series of bicyclic thiazoline derivatives (4a-s) was synthesized and evaluated for hepatoprotective activity against galactosamine-induced and monoclonal antibody-induced acute liver injuries in rats. The structure-activity relationships were investigated. Among the compounds synthesized, ethyl 3-(N-methylcarbamoyl)-5,6-dihydrothiazolo[2,3-c][1,4]thiazin e-8- carboxylate (4p) exhibited remarkable hepatoprotective activity and lower toxicity. This compound suppressed galactosamine-induced hepatic injury at 100 mg/kg by gavage and further prevented monoclonal antibody-induced hepatic injury at 30 mg/kg by intraperitoneal injection, as evaluated by measuring changes in serum transaminase activities.

Increased carcinoembryonic antigen concentrations in sera and bronchoalveolar lavage fluids of patients with pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is a rare disease in which alveoli are filled with lipoproteinaceous materials. We measured carcinoembryonic antigen (CEA) concentrations in bronchoalveolar lavage (BAL) fluids and sera from patients with PAP and from healthy volunteers (HV). Significantly increased CEA values were found in BAL fluids and sera from patients with PAP compared with those from HV. BAL fluid CEA values significantly correlated to serum CEA values in patients with PAP. Serum CEA values significantly correlated to serum lactate dehydrogenase activity and alveolar-arterial PO2 difference values in patients with PAP. Successive measurements of serum CEA showed that serum CEA values reflect the disease activity of PAP. The determination of serum CEA is useful for evaluating disease severity of PAP.

Design of a new disposable ERG electrode

A new electrode for electroretinography (ERG) has been produced. The new device made of gold filament was applied as corneal and noncorneal electrod. Flash ERG and pattern ERG were recorded in normal subjects using this new electrode and compared with those made by available electrodes. There were so significant differences in amplitude and latency between the new electrode placed on the cornea and the JET-type electrode. For pattern ERG there were no significant differences between the new electrode placed in the lower fornix and a gold-foil-type electrode. As this new electrode is less expensive and more comfortable than the available electrodes, it is clinically useful.

Plasma concentrations of atrial natriuretic peptide in cardioembolic stroke with atrial fibrillation

The aim of the present study was to determine whether the level of plasma atrial natriuretic peptide (ANP), an indicator of atrial stretching, correlates with the formation of a thrombus in the left atrium during cardioembolic stroke with atrial fibrillation. Plasma concentrations of immunoreactive ANP and thrombin-antithrombin III complex (TAT) were measured in five age-matched groups including: 16 patients with acute cardioembolic stroke and atrial fibrillation (group 1), 26 patients with chronic cardioembolic stroke and atrial fibrillation (group 2), 27 patients with atrial fibrillation without previous stroke (group 3), 21 patients with acute lacunar stroke (group 4), and 27 healthy controls. The plasma ANP levels were higher in group 1, regardless of the stage, than those estimated at chronic stage in group 4 and in healthy controls. There were no stage-related differences between groups 1, 2 and 3. Plasma levels of ANP in group 2, a high risk group of cardioembolic stroke, were higher than in group 3, a low risk group. There was no correlation between plasma levels of ANP and mean blood pressure, pulse rate or plasma levels of TAT in any group. These results indicate that the determination of plasma ANP concentration is useful to distinguish a high risk patient from a low risk patient and also a cardioembolic stroke patient from a lacunar stroke patient. They also underscore the difficulties in recognizing left atrial thrombus formation by determining the plasma ANP concentration in cardioembolic stroke.

Increased production of transforming growth factor-beta 2 from cultured human retinal pigment epithelial cells by photocoagulation

PURPOSE

To examine whether laser photocoagulation increased production of growth factors and cytokines, especially transforming growth factor-beta 2 (TGF-beta 2), by cultured human retinal pigment epithelial (RPE) cells.

METHODS

Dot blot analysis was performed to identify the changes using the conditioned medium of cultured human RPE cells with or without laser photocoagulation. The following growth factors and cytokines were examined: TGF-beta 1, TGF-beta 2, platelet-derived growth factor-BB, epidermal growth factor, interleukin-1 beta, tumor necrosis factor-alpha, and basic fibroblast growth factor. Immunostaining of the photocoagulated RPE cells was also performed by using the antibodies. Growth inhibition assay using mink lung epithelial cells (CCL-64) was employed both to quantitate active and latent forms of TGF-beta 2 secreted in the conditioned media and to determine the type of TGF-beta by using a neutralizing antibody.

RESULTS

In dot blot analysis, among the growth factors and cytokines examined, production of TGF-beta 2 was changed most markedly by laser photocoagulation. This result agreed with the immunocytochemical staining pattern. Photocoagulated RPE-conditioned medium inhibited [3H]-thymidine incorporation of CCL-64. The inhibitory activity was blocked by a neutralizing antibody to TGF-beta 2. Production of active TGF-beta 2 was increased from 1.0 pg/cm2 +/- 0.6 pg/cm2 per 24 hours to 11.0 pg/cm2 +/- 1.0 pg/cm2 per 24 hours by laser photocoagulation, and that of total TGF-beta 2 was increased from 11 pg/cm2 +/- 1.0 pg/cm2 per 24 hours to 100 pg/cm2 +/- 20.1 pg/cm2 per 24 hours.

CONCLUSIONS

Laser photocoagulation of cultured RPE cells increases their production of TGF-beta 2. It thus seems possible that the TGF-beta 2 produced by the RPE cells plays an important role in the processes that occur after laser photocoagulation.

Posterior lenticonus, corneal opacity, glaucoma and preretinal membrane in a young woman

A case of posterior lenticonus with corneal opacity, glaucoma and preretinal membrane is presented. Gonioscopic findings and slit-lamp examination suggested that angle closure due to a large volume of the lens may have caused high intraocular pressure levels. Also, refractive error, exotropia and bilateral nystagmus were accompanied by posterior lenticonus in this case. Our case demonstrates a rare combination of abnormalities involving various ocular structures.

Plasma lipoprotein (a) levels and fibrinolytic activity in acute myocardial infarction

To evaluate the effects of lipoprotein (a) [Lp (a)] on the fibrinolytic system in patients with acute myocardial infarction (AMI) who underwent thrombolytic therapy with recombinant tissue-type plasminogen activator, we examined serial changes in plasma levels of Lp (a), plasminogen activator inhibitor (PAI) activity, alpha 2-plasmin inhibitor-plasmin complex (PIC) and thrombin antithrombin III complex (TAT) in venous plasma samples from 25 patients with AMI for 3 weeks. Plasma Lp (a) levels were significantly increased 5, 7, and 14 days after admission and tended to decrease by the 21st day. On the other hand, the ratio of PIC/TAT was significantly increased on the 7th day and remained high for 3 weeks (p < 0.01), while plasma PAI activity was significantly decreased on the 5th day after admission (p < 0.01). Thus, plasma fibrinolytic function is impaired in the early phase after AMI, and gradually improves over the course of 3 weeks. The increase in plasma Lp (a) levels is, therefore, not accompanied by a significant decrease in plasma fibrinolytic function in patients with AMI.

Ruptured distal anterior inferior cerebellar artery aneurysm--case report

A 62-year-old female presented with a distal anterior inferior cerebellar artery (AICA) aneurysm showing severe involvement of the facial and acoustic nerves manifesting as progressive left hearing disturbance and left facial nerve paresis. She was admitted to our hospital 2 months after the onset. A saccular aneurysm arising from the meatal loop of AICA was found between the facial and acoustic nerves which were damaged directly by the aneurysm. Magnetic resonance imaging demonstrated a vascular anomaly, differentiating this disorder from cerebellopontine angle tumor, and evidence of an old subarachnoid clot. These characteristics were extremely helpful for the differential diagnosis. Neck clipping and aneurysmectomy were performed to achieve decompression of the cranial nerves. One year and 2 months later full function of the facial nerve returned but the hearing disturbance persisted.

Glial-, neuronal- and photoreceptor-specific cell markers in rosettes of retinoblastoma and retinal dysplasia

Previous studies have shown that a rosette formation represents an attempt to form embryonic retinal tissue, primarily rods and cones. To test the theories as to the origin and characteristics of retinoblastoma cells, we compared the characteristics of tumor rosettes with those of dysplastic rosettes seen in retinal dysplasia using the glial, neuronal and photoreceptor markers. Forty-four retinoblastoma and one retinal dysplasia specimens were analyzed by indirect immunohistochemistry, using specific antibodies against glial fibrillary acidic protein, S-100 protein, myelin basic protein, neuron-specific enolase, neurofilament, retinal S-antigen and retinal pigment epithelial antigen. In human retinoblastoma, all the glial, neuronal, retinal pigment epithelial, and photoreceptor cell markers, except for the neurofilament, were present in parts of rosette-forming tumor cells. However, their localization was different for each antigen and it was not clear whether each tumor cell possesses several antigens. These immuno-positive tumor cells were cytologically indistinguishable from other rosette-forming cells at the light microscopic level. In retinal dysplasia, neuron specific enolase and retinal S-antigen were diffusely expressed in the dysplastic rosettes, however, other antigen were not seen in those rosettes. The staining pattern by immunocytochemistry is totally different in tumor rosettes from dysplastic ones. We found varying localizations of different immunoreactivities within tumor rosettes. These results led us to suggest that tumor cells in the rosettes of retinoblastoma may have the ability to differentiate into neural and glial cells. To prove the theory that retinoblastoma cells may have originated from a primitive neuroectodermal cell capable of multipotentiality, further investigation is needed.

Serial electrocardiographic findings in acute myocarditis

The purpose of the present study was to clarify the characteristic findings of electrocardiogram (ECG) in 11 patients with acute myocarditis. ST elevation without reciprocal ST depression was one of the conspicuous findings in the acute stage. Total QRS amplitudes at the acute stage were significantly decreased as compared to those before illness and during the convalescent stage. Abnormal Q waves were present in 7 patients and disappeared in a short period. The number of leads showing Q waves was inversely correlated to left ventricular (LV) ejection fraction (r = -0.87, p < 0.01). Conduction disturbances were present in 7 patients. Second degree and advanced AV block was transient while bundle branch block remained over months. Corticosteroid treatment was effective for patients who had edematous myocardial thickening and AV conduction disturbances. As the serial ECG findings in acute myocarditis are so characteristic, and this help to differentiate it from acute myocardial infarction (AMI).

Analysis of electroretinogram during systemic hypercapnia with intraretinal K(+)-microelectrodes in cats

PURPOSE

Systemic hypercapnia alters the intraretinal pH and metabolism and profoundly affects the vitreal electroretinogram (ERG). Using intraretinal K(+)-selective microelectrodes (ISMs), the authors examined the effects of systemic hypercapnia on ERG in the intact cat eye in vivo.

METHODS

Double-barreled K(+)-ISMs were used to record intraretinal, light-evoked [K+]o decrease, intraretinal ERG, vitreal ERG, and standing potential (SP) in the dark-adapted retina. Hypercapnia was induced by adding CO2 to the inhaled mixture of gas (without significant hypoxia).

RESULTS

The standing potential was elevated, and the vitreal ERG c-wave increased in amplitude whereas the b-wave decreased during hypercapnia. Intraretinal recordings showed that the amplitudes of slow PIII and the transepithelial (TEP) c-wave decreased. The slow PIII decreased more than the TEP c-wave. The light-evoked [K+]o decrease also was reduced, but no change was noted in the subretinal [K+]o.

CONCLUSION

The neural retina was more sensitive than the retinal pigment epithelium to the intraretinal acidification caused by systemic hypercapnia. However, the change in the SP and b-wave suggested complicated effects other than acidosis.

Scleral plug of biodegradable polymers for controlled drug release in the vitreous

We designed a new device, a scleral plug, that releases drugs into the vitreous after being implanted and fixed at the pars plana. Use of the plug for provision of doxorubicin hydrochloride was evaluated in rabbits. The scleral plug (8.5 mg) was made of poly(lactic-glycolic acid) (molecular weight, 40,000 daltons) containing 1% doxorubicin. Vitreous concentrations of doxorubicin were measured after the implantation. In vitro studies showed that the plug released 26% of the drug during 4 weeks. In vivo studies demonstrated that the concentration in the vitreous humor was maintained at a therapeutic range for longer than 4 weeks. No substantial toxic reactions were observed by electroretinographic and histopathologic evaluations. Our findings suggested that a scleral plug made of biodegradable polymers is a promising device for a controlled drug-release system in the vitreous.

Combined testosterone treatment in pubertal and adult periods induces male-specific acetohexamide reductase activity in liver microsomes of female rats

The influence of testosterone treatment on acetohexamide reductase activities in liver microsomes and cytosol of female rats was examined. Acetohexamide reductase activity in liver microsomes was much lower in female rats than in male rats. Combined testosterone treatment in pubertal and adult periods induced male-specific acetohexamide reductase activity in liver microsomes of female rats. However, testosterone treatment only during puberty or during adulthood was without effect. Testosterone secreted from the testes during puberty appeared to have a significant effect similar to neonatal imprinting in the induction of acetohexamide reductase activity in liver microsomes of female rats. The combined testosterone treatment, or testosterone treatment only during puberty or during adulthood had no effect on acetohexamide reductase activity in liver cytosol of female rats.

The long-term growth rate of residual acoustic neurinomas

The growth rate of 19 residual acoustic neurinomas was examined in a long-term follow-up study (median, 10 years; range, 5 to 17 years) following intracapsular removal. Of these, 10 (53%) had regrowth, three (16%) showed regression, and six (32%) were unchanged. The 10 acoustic neurinomas showing regrowth were divided into two categories, either solid or cystic, according to computed tomographic findings. Five acoustic neurinomas with cyst formation showed rapid regrowth, with the tumour doubling time ranging from 0.15 to 5.0 years (median, 4.5 years), and required re-operation. Five solid tumours showed slow regrowth, with the tumour doubling time ranging from 9 to 34 years (median, 15 years). Although cyst formation is a major factor in rapid regrowth, residual acoustic neurinomas without cyst formation have a slower growth potential. In this study, 74% of the residual acoustic neurinomas have never required re-operation. It is advisable to choose intracapsular removal if there is major risk of neurological deficits.

[Usefulness and limitations of dobutamine stress echocardiography for detection of coronary artery disease]

The value of dobutamine stress echocardiography for detecting coronary artery disease was evaluated in 67 patients with normal left ventricular wall motion at rest who also underwent quantitative angiography. The overall sensitivity and specificity of dobutamine stress echocardiography for detecting coronary artery disease were 83% and 70%, respectively. The sensitivities for detecting multivessel disease and single vessel disease were 92% and 76%, respectively. The sensitivity of dobutamine stress echocardiography was 91% in patients treated without beta-blocker, and 70% in patients treated with beta-blocker (p < 0.001). The relatively low peak heart rate during dobutamine infusion in patients treated with beta-blocker seems to affect the sensitivity of dobutamine stress echocardiography. There were no severe complications during dobutamine infusion. Dobutamine stress echocardiography is a safe and accurate method for detecting coronary artery disease. However, an additional technique to increase peak heart rate in patients treated with beta-blocker such as injection of atropin should be considered.

The role of nitric oxide synthase in endotoxin-induced uveitis: effects of NG-nitro L-arginine

PURPOSE

To evaluate the role of nitric oxide synthase (NOS) in endotoxin-induced uveitis (EIU).

METHODS

EIU was caused in Lewis rats by injecting lipopolysaccharide (LPS) into the foot pad, and the effects of an NOS inhibitor, NG-nitro L-arginine (NA), was comparatively studied by the simultaneous administration of NA and LPS. Total NOS and inducible NOS (iNOS) activities were differentially assayed in the anterior segment of the eye in EIU with and without NA treatment. The effects of NA on EIU were also evaluated by clinical manifestation, histology, and protein concentration in the aqueous humor.

RESULTS

In untreated rats, there was no significant iNOS activity. With the EIU model, iNOS activity showed a marked increase in the anterior segment of the eye, reaching a maximum 9 hours after LPS injection (10,850 +/- 1,650 cpm/mg protein, mean +/- SEM). NA reduced the iNOS activity 9 hours after injection to 2,400 +/- 90 cpm/mg protein (P < 0.001). Aqueous humor protein concentration in the EIU model was 10.6 +/- 0.75 mg/ml, and the cell number was 216 +/- 12 cells/microliters. NA significantly reduced these factors to 4.25 +/- 0.48 mg/microliters for the protein concentration (P < 0.0005) and 25 +/- 6 cells/ml for the cell number (P < 0.0005). Histologic studies showed less prominent infiltration of polymorphonuclear cells in the anterior uvea than for conventional EIU.

CONCLUSIONS

Induction of iNOS may play a key role in the pathogenesis of EIU. Because inhibition of iNOS activity reduced the inflammatory response, suppression of NO formation may inhibit the development of EIU.

Endothelin-1 promotes corneal epithelial wound healing in rabbits

This study is an attempt to determine the effect of endothelin-1 (ET-1)-containing eyedrops on the rate of corneal epithelial wound closure in rabbits. After corneal epithelial debridement of about 50-60 mm2 with n-heptanol, eyedrops containing either 10(-8) M ET-1 or 10(-6) M ET-1 were applied at five different times for the next three days. The wound was serially photographed 12, 24, 36, 48, 60 and 72 hours later to measure the extent of healing with a computerized planimeter. The respective wound healing rate at 10(-6) and 10(-8) M ET-1 was 1.293 +/- 0.040 mm2/hour (n = 11) and 1.262 +/- 0.087 mm2/hour (n = 6), respectively. These rates were 29% (p < 0.01) and 26% (p < 0.05) above the control value, 1.005 +/- 0.063 mm2/hour (n = 13). Reepithelialization was not associated with any epithelial hyperplasia, neovascularization or conjunctival hyperemia. These results suggest that ET-1-containing eyedrops could be of therapeutic value in the remedy of corneal epithelial defects.

[A case of pulmonary actinomycosis; histological diagnosis obtained from transbronchial lung biopsy specimen]

We report the first case of pulmonary actinomycosis that was diagnosed by histological findings of transbronchial lung biopsy specimen. A 60-year-old man was admitted because of cough and bloody sputa. His chest roentgenogram and CT scan revealed a cavitary opacity in the apex of the left lung. Histological findings of the biopsy specimen showed multiple basophilic actinomyces granules accompanied by an acute inflammatory exudate, confirming the diagnosis of pulmonary actinomycosis. We prescribed antibiotic treatment and a good response was obtained.

Mitochondrial induction of adult T cell leukemia derived factor (ADF/hTx) after oxidative stresses in retinal pigment epithelial cells

PURPOSE

Adult T cell leukemia derived factor (ADF) is a human homologue of thioredoxin (hTx), which exhibits scavenging activity with reactive oxygen intermediates. In their previous study, the authors found that after transient retinal ischemia, the expression of thioredoxin in rat retinal pigment epithelium (RPE) layer increased markedly. The present investigation is to determine intracellular ADF localization in RPE after transient ischemia and in cultured human RPE cells after oxidative insult by H2O2.

METHODS

The authors employed immunoelectron microscopy to examine ADF localization in RPE. Labeling density analysis was performed to supplement the main observation in the experiment of transient retinal ischemia. 3-(4,5-dimethylthiazol-2yl)-2-5-diphenyltetrazolium bromide (MTT) assay was performed to verify the protective role of recombinant ADF (rADF) against H2O2.

RESULTS

In immunogold electron microscopy, sparse ADF-positive labeling was seen in the cytosol and mitochondria in normal rat RPE and in untreated cultured RPE cells. After oxidative stress, it was concentrated in mitochondria in both groups. MTT assay proved that rADF protected cultured RPE from the toxicity of H2O2.

CONCLUSIONS

This study shows the induction of ADF/hTx in mitochondria of RPE after oxidative stresses and its protective effect on cultured RPE exposed to H2O2. The data indicate the possibly important role of ADF/hTx in the protection of retinal cells from the oxidative stresses associated with retinal ischemic disease and probably with regular visual activity.