Guanidine hydrochloride-induced denaturation of Pseudomonas cepacia lipase

The guanidine hydrochloride-induced denaturation of Pseudomonas cepacia lipase (PCL) was studied at pH 7 by monitoring the changes in the fluorescence and circular dichroism of the enzyme. The denaturation was irreversible as a whole, and the addition of Ca2+ ions decreased the velocity of the denaturation. The denaturation process was well explained consistently by a two-step mechanism, as follows: [see equation in text] where N is the native state of PCL, D(I) an intermediate denatured-state which can be refolded into the native state, and D(F) the final denatured-state that can not be renatured. Ethanol (10%) increased the denaturation velocity by decreasing the refolding step, D(I) + Ca2+ --> N x Ca2+, which would be caused by the stabilization of D(I) by ethanol.

Expression of transforming growth factor-beta superfamily receptors in developing rat eyes

PURPOSE

To ascertain the role played by the transforming growth factor (TGF)-beta superfamily in retinal development by determining the changes in the expression patterns of their receptors during development of the normal rat retina.

METHODS

The expression of type I and type II receptors of the TGF-beta superfamily was observed at the protein level in rat eyes at embryonic age 17 days (E17), at birth (P0), at postnatal days 3, 6, 9, and at 11 weeks (P3, P6, P9, and adult, respectively).

RESULTS

Activin type I receptor and BMP type IB receptor were first detected in P6 and P3 retinas, respectively, at the protein level, and activin type II receptor was first detected in the P0 retina. The other receptors (TGF-beta type I and II receptors, activin type IB receptor, BMP types IA and II receptors) were detected at E17. The period from P0 to P9 corresponded to the period of dynamic changes in the rat retinal development.

CONCLUSION

The results suggest that the expression of TGF-beta superfamily is regulated along with retinal development and may be related to retinal development.

NF-kappaB involvement in the activation of primary adult T-cell leukemia cells and its clinical implications

The HTLV-I provirus-encoded Tax protein induces NF-kappaB in Tax-transfected Jurkat T cells or HTLVL-I- infected T cells in vitro. Tax induction of NF-kappaB is presumed to be involved in proliferation and activation of primary leukemia cells in vivo. Recent studies have demonstrated that NF-kappaB activities in human T cells are mediated by at least four c-Rel-related DNA binding proteins - p50, p55, p75 and p85. We examined the significance of NF-kappaB induction in primary adult T cell leukemia cells and the induction kinetics of each of the four NF-kappaB species. Marked NF-kappaB activity was detected using an electrophoretic mobility shift assay (EMSA) in the primary cells of patients with acute disease, but little activity was noted in the cells of chronic patients. NF-kappaB activity was enhanced in a time-dependent manner in acute type cells cultured with mitogen-free medium; there was no induction of activity in chronic type cells. UV crosslinking demonstrated all four species of NFkappaB complex - high levels of p50 and lower levels of p55 and p75, in acute type cells; chronic type cells showed only the p50. As a control, normal resting T cells similarly showed only p50; control cells showed little change in activity when cultured without mitogenic stimulation, analogous to chronic type ATL. Northern blotting revealed enhancement of c-rel (encoding p85) and KBFI (encoding p50 and p55) expression in acute type cells during culture, while there was no significant enhancement of mRNAs in chronic type ATL cells or unstimulated normal T cells. Northern blotting also revealed that Tax is upregulated at the mRNA level in acute- but not chronic-type cells during culture. Expression of c-rel and KBF1 mRNAs in acute type cells appeared to be related to Tax mRNA expression. These results suggest that Tax is capable of inducing nuclear expression of all four NF-kappaB species in primary ATL cells of acute type patients, with marked effects on p55, p75, and p85. Tax induction of NF-kappaB species is regulated, at least in part, at a pretranslational level involving increases in c-rel and KBF1 mRNA.

[Labyrinthine fistulas in cholesteatoma]

The purpose of the present study was to investigate the clinical features of cases of cholesteatoma with labyrinthine fistulas, and in particular the pre and post-operative bone-conduction (BC). Cholestatoma patients with bone erosion or a defect found in the first stage operation were analyzed. The operations were conducted between 1992 and 1996. The patients were classified into four types, I, IIa, IIb, and III, according to Dornhoffer and Milewski's classification, which is based on different stages in the bone defect. A type I fistula is an erosion of the bony labyrinth with an intact endosteum. Type IIa is accompanied by an opened perilymphatic space with undisturbed perilymph while type IIb has a disturbed perilymph. A Type III fistula is an opened perilymphatic space with a disturbance of the underlying membranous labyrinth. Only 24 patients with type II and type III fistulas were included in this study. The location of the fistulas was the semicircular canals (SCCs) or/and the vestibula in 21 patients and in the cochlea in 3 patients. We examined the fistula by high-resolution computed tomography scan (CT scan) with 1 mm slice and 1 mm width axial-sections in 14 patients. A bone defect in the labyrinth was detected in 10 cases (71.5%) pre-operatively. Pre-operative BC was worse in the patients with cochlear fistulas than in those with fistulas located in SCCs or the vestibula. Within this latter group there were 13 type IIa (group IIa), patients and 8 type IIb or III (group IIb or III) patients. However, there was no difference in the pre-operative BC between these two sub-groups Tympanoplasty was conducted in all 24 patients. The postoperative BC of group IIa and group IIb or III were compared. Two of the 13 patients in group II a (15.4%) and 3 of 8 in group IIb or III (37.5%) had a deteriorated postoperative BC. Statistical analysis revealed that the postoperative BC was more inclined to become worse in patients with advanced stage IIb or III fistulas.

Airway inflammation, exhaled nitric oxide, and severity of asthma in patients with western red cedar asthma

Examination of induced sputum and measurement of exhaled NO have been advocated as noninvasive methods of assessing the degree of airway inflammation. In this study, we performed follow-up evaluation on 71 subjects with asthma caused by exposure to Western red cedar; 50 subjects had left exposure, whereas the rest continued to work in the same job. Spirometry, methacholine challenge tests, exhaled nitric oxide, and sputum induction were carried out. Of the 50 subjects who left exposure, 12 had no respiratory impairment according to the American Throacic Society guidelines for assessing respiratory impairment in patients with asthma, 17 belonged to Class 1, 12 to Class 2, five to Class 3, and four to Class 4. The percentage of eosinophils in induced sputum showed a significant inverse relationship with FEV1 (r = -0.46, p < 0.001), and a significant positive correlation with levels of exhaled NO (r = 0.42, p < 0.001) and with the class of respiratory impairment (r = 0.52, p < 0.001). Mean percent eosinophils were 1.5 for impairment Class 0, 2.2 for Class 1, 1.7 for Class 2, 6.8 for Class 3, and 16.3 for Class 4. No relationship was found between the levels of exhaled NO and the functional parameters as well as the impairment class. NO levels in ppb were 21 for impairment Class 0, 30 for Class 1, 22 for Class 2, 26 for Class 3, and 49 for Class 4. This study also provides objective evidence that airway inflammation, as indicated by induced sputum, corroborates the rating of respiratory impairment in patients with asthma.

[Biochemical and molecular characterization of Salmonella ser. enteritidis phage type 1 isolated from food poisoning outbreaks in Tokyo]

Since the first outbreak in 1990, the incidence of Salmonella ser. Enteritidis (S. Enteritidis) phage type (PT) 1 food poisoning has gradually increased in Tokyo and has reached approximately 30% of the total S. Enteritidis outbreaks reported. To characterise these S. Enteritidis PT1 food poisoning, a total of 198 strains obtained from 44 outbreaks between 1990 and 1996 were examined for antimicrobial resistance, acid producibility from glycols (propylene and ethylene glycol) and plasmid DNA profiles. The 44 PT1 outbreaks analysed were further subdivided into 11 types by epidemiological markers. The most common patterns were type A (plasmid profile carrying only one plasmid (60 kb). SM and TC resistance and non producibility from glycols), and type B (plasmid profile carrying two plasmids (60 and 20 kb), SM resistance and no producibility from glycols) and were responsible for 21 (47.7%) and 15 (34.1%) outbreaks, respectively. In 11 of 44 outbreaks, strains carrying identical epidemiological markers were isolated both from patients and vehicle foods, environments, and/or food-handlers. Similar to PT4 and PT34 outbreaks reported in Japan, egg and egg-related foods were also suspected in 8 of these 11 outbreaks. Of interest, chicken which were not pointed out in PT4 and PT 34 outbreaks was also suspected as a vehicle of transmission in two outbreaks.

Creating cataract in a pig eye

The purpose of this study was to create a uniform, reproducible hardened lens nucleus and an anterior capsule in a pig eye that approximate those in the human eye for use in cataract surgery training. The lens nuclei was hardened and anterior capsule elasticity was reduced in pig eyes by injecting the lens with mixtures of formalin and alcohol (ethanol, 2-propanol, or both). A 30 gauge needle was used to pierce the lens 3.0 mm from the limbus. Then, 0.2 mL of the formalin and alcohol mixture was injected. The most effective mixture was formalin, ethanol, and 2-propanol in the ratio 4:3:3. Fifteen minutes after this mixture was injected, the pig eye had nuclear cataract with grade III hardness and an anterior capsule that approximated the capsule in a human cataractous eye. The cataract created by this method will be useful in teaching continuous curvilinear capsulorhexis, divide and conquer and phaco chop phacoemulsification, and nuclear hydrodelineation and rotation.

Expression of transforming growth factor-beta superfamily receptors in rat eyes

PURPOSE

Transforming growth factor-beta (TGF-beta) superfamily consists of many multifunctional cytokines including TGF-beta, activins, and bone morphogenetic proteins (BMPs). Previous reports show that these factors are expressed in ocular tissue, and exert their effects through type I and type II serine/threonine type receptors. The purpose of this study is to observe the expression of these receptor families in normal rat eyes as the first step in investigating the functions of TGF-beta superfamily members in ocular tissue.

METHODS

The expression of receptors was examined immunohistochemically in one eye each of 6 Lewis rats. The type I receptors examined were the TGF-beta type I receptor (TbetaR-I), activin type I receptor (ActR-I), activin type IB receptor (ActR-IB), bone BMP type IA receptor (BMPR-IA), BMP type IB receptor (BMPR-IB), and activin receptor-like kinase-1 (ALK-1). The type II receptors examined were TGF-beta type II receptor (TbetaR-II), activin type II receptor (ActR-II), and BMP type II receptor (BMPR-II).

RESULTS

All 6 type I receptors, ActR-II and the alternative spliced long version of BMPR-II were expressed in the following cells: corneal and conjunctival epithelium, corneal keratocytes, corneal endothelium, epithelium of iris and ciliary body, epithelium of lens, sensory retina excluding the outer segments of photoreceptors, retinal pigment epithelium (RPE), and vascular cells. TbetaR-II and the short version of BMPR-II (truncated form) were expressed in the outer segments of the photoreceptors in addition to the above. The results of staining were similar in all the sections examined.

CONCLUSIONS

The cornea, ciliary body, iris, lens, retinal cells, RPE and vascular cells expressed the receptors for TGF-beta superfamily at protein level.

The effect of intrathecal magnesium sulphate on nociception in rat acute pain models

We examined the antinociceptive effect of intrathecally administered magnesium sulphate (MgSO4) in rats, using acute pain models including mechanical pressure, heat and subcutaneous formalin injection. According to the locomotion test 10 microliters of 6.2% MgSO4 did not produce motor paralysis. At the same dose, responses to pressure and heat were intact, compared with controls given saline. MgSO4 produced depression of pain responses only after the first 10 min in the formalin test. Our studies indicated that MgSO4 did not show remarkable antinociceptive effects in acute pain models.

Identification of a novel ice-nucleating bacterium of Antarctic origin and its ice nucleation properties

A novel ice-nucleating bacterium (INB) was isolated from Ross Island, Antarctica. INBs could be isolated more frequently than was generally thought. INB strain IN-74 was found in the white colony group. Strain IN-74 was identified from its taxonomic characteristics as a novel INB, Pseudomonas antarctica IN-74. When strain IN-74 was cultured aerobically in a medium consisting of the ice-nucleating broth (pH 7.0) for 6 days at 4 degrees C, the ice-nucleating activity of strain IN-74 cells was obtained. Strain IN-74 cells produced ice nuclei only at extremely low growth temperatures. The nuclei appeared to be less thermolabile than those of INB Pseudomonas fluorescens KUIN-1. The freezing difference spectra in D2O and H2O at ice-nucleating temperature for strain IN-74 cells and conventional INBs (Pseudomonas fluorescens KUIN-1, Pseudomonas viridiflava KUIN-2, and Pseudomonas syringae C-9) exhibited different curves.

Sputum eosinophils and exhaled nitric oxide during late asthmatic reaction in patients with western red cedar asthma

Examination of sputum for eosinophils and measurement of exhaled nitric oxide have been proposed as noninvasive methods of assessing airway inflammation in asthma. The use of these tests in the evaluation of patients with occupational asthma has not been reported. This study investigated the changes in sputum eosinophils and exhaled NO before and at intervals after inhalation challenge with plicatic acid in patients with suspected western red cedar asthma. Of 17 subjects who underwent challenge, nine had a positive bronchoconstrictor reaction (responders) and eight had a negative reaction (nonresponders). At 6 and 24 h after plicatic acid challenge, there was a significant increase in sputum eosinophils among responders, which was inversely related to the fall in forced expiratory volume in one second (FEV1) at 6 h. An increase in sputum eosinophils was also found in three nonresponders. Levels of exhaled NO increased at 24 h after challenge with plicatic acid in both responders and nonresponders, being significant only in nonresponders. No correlation was found between the increase in nitric oxide and the magnitude of the functional changes in the airways. There were significant correlations between the degree of sputum eosinophilia and the level of exhaled NO before and after methacholine and plicatic acid challenge. In conclusion, the late asthmatic reaction induced by plicatic acid in patients with western red cedar asthma is associated with an increase in sputum eosinophils. The usefulness of measuring sputum eosinophils and exhaled nitric oxide in the clinical evaluation of patients with suspected occupational asthma caused by low molecular weight compounds has yet to be determined.

Possibility for discriminating between two representative non two-state thermal unfolding models of proteins by DSC

Possible differences between two representative non two-state thermal unfolding mechanisms of protein are discussed concerning differential scanning calorimetry. Numerical simulations showed that, by DSC measurement, it is hard to discriminate between the independent model, which assumes independent unfolding domains in a protein, and the sequential model, which assumes intermediate(s) between native and denatured states, especially when values of molecular weight, denaturation enthalpy, and difference in denaturation temperature of each denaturation process are large. DSC curve analysis of Aspergillus niger glucoamylase based on these two models gave essentially the same thermodynamic parameters.

Exposure and sensitization to cat dander: asthma and asthma-like symptoms among adults

BACKGROUND

Several pets, such as cats, dogs, and rodents, are known to produce allergens. Despite the clinical and laboratory evidence that exposure to pets can cause bronchoconstriction in sensitized subjects, the results of population studies have been contradictory.

OBJECTIVES

The purpose of this study was to investigate the relationship between cat ownership and the prevalence of asthma, asthma-like symptoms, and bronchitic symptoms among subjects 20 to 44 years of age in Vancouver, Canada and to determine whether sensitization is responsible for such an association.

METHODS

Two thousand nine hundred ninety-nine (88%) randomly selected subjects responded to a mail questionnaire. Of these, 504 participated in laboratory examination, including allergy skin testing.

RESULTS

One thousand nineteen study responders (34%) were pet owners at the time of the study (current owners). Current pet owners were found to have a higher prevalence of current asthma, asthma-like symptoms, and bronchitic symptoms compared with those without pets. Cat owners had significantly higher risk of having current asthma and asthma-like symptoms. In the subset who had allergic skin tests, we found that those who were allergic to cat dander had a significantly higher risk of current asthma than those not allergic to cat dander and not owning a cat.

CONCLUSION

This study provides evidence that sensitization to cat dander is a more important risk factor for current asthma and asthma-like symptoms than cat ownership itself.

High predictive value of red cell volume measurement using carboxy-haemoglobin in a rabbit model of haemorrhage

We have studied the accuracy of blood volume measurements using carbon monoxide (CO)-labelled haemoglobin (COHb) injection and dilution (CO method) by comparing changes in red cell volume (RCV) measured using the CO method and 51Cr-labelled erythrocyte dilution (51Cr method) in a haemorrhage and infusion model in rabbits. RCV was measured repeatedly using the CO method at four different blood volume stages (stages I-IV). At stages I and IV, RCV was measured simultaneously using the 51Cr method. In comparing the sum of the circulating RCV and extracted RCV (SUM RCV) using the CO method, the values were almost equal and there were no significant differences between the values at the four stages. In comparing circulating RCV measured using the CO method and the 51Cr method, mean difference between the two methods was 0.80 (SD 0.76) ml kg-1 or 4.7 (4.6)%, and a positive correlation was observed (r = 0.91). We conclude that the CO method can be used to measure blood volume during perioperative periods in infants because it avoids use of a radioactive tracer, is simple and repeated measurements are possible.

Effects of transforming growth factor beta on corneal epithelial and stromal cell function in a rat wound healing model after excimer laser keratectomy

BACKGROUND

Transforming growth factor beta (TGF-beta) regulates extracellular matrix deposition, cell proliferation, and migration, and is expressed in cornea. TGF-beta is thought to be involved in the corneal wound healing process.

METHODS

The central corneal area (3 mm in diameter) of Lewis rats was ablated using PTK mode excimer laser and the wound healing process was observed at 12 and 24 h and 2, 5, 10, and 30 days after treatment. The expression of TGF-beta 1, -beta 2 and -beta 3, TGF-beta type I and type II receptors, alpha 3, alpha 5, beta 4 integrin subunits, laminin and fibronectin was studied immunohistochemically. Antibody neutralizing TGF-beta 1, -beta 2 and -beta 3 was administered intraperitoneally, 50 micrograms daily, for 5 days after the laser treatment to investigate the effects of TGF-beta function blockade.

RESULTS

At the leading edge of the regenerating epithelium, no TGF-beta type I and type II receptors and beta 4 integrin subunits were expressed after 24 h. Regenerating epithelium covered the ablated area after 2 days. An abnormal fibrotic layer was formed in the subepithelial area. This layer contained round-shaped cells in the stroma in the early stage (2-5 days after laser ablation) and spindle-shaped fibroblast-like keratocytes after 10 days. Laminin and fibronectin expression increased in the fibrotic layer. The increased stromal cells expressed TGF-beta isoforms and TGF-beta receptors. Neutralizing TGF-beta inhibited the stromal cell increase in the laser ablated area after 5 days.

CONCLUSION

TGF-beta may be involved in epithelial cell migration and stromal cell reaction during the corneal wound healing process after excimer laser ablation in rat models.

Purification and characterization of a novel cold-regulated protein from an ice-nucleating bacterium, Pseudomonas fluorescens KUIN-1

The psychrotrophic ice-nucleating bacterium, Pseudomonas fluorescens KUIN-1 respond to a decrease in temperature with the induction of proteins that are classified as cold shock proteins (CSPs). We found the function of a 26-kDa protein of the CSPs in the strain KUIN-1. In strain KUIN-1, a cold shock from 18 to 4 degrees C induced the synthesis of the 26-kDa protein. By analysis with SDS-PAGE, it was then demonstrated that the 26-kDa protein was produced by the cells after treatment at 4 degrees C. The 26-kDa protein was purified to apparent homogeneity by (NH4)2SO4 precipitation and some chromatographies (QA52, phenyl Superose, Superose 12, and Mono Q). The purified 26-kDa protein is composed of 6 subunits of 26.5-kDa with a molecular mass of approximately 159-kDa according to gel filtration and SDS-PAGE. The N-terminal sequence of the 26-kDa protein was Gln-Ala-Ala-Tyr-Tyr-Pro-Ala-His-His-His-Gln- Gln-Val-Gln-Gln-His-Trp-Gly-His-His-. Specifically, 26-kDa protein of the CSPs of strain KUIN-1 was very effective in protecting the cold-labile enzyme, lactate dehydrogenase against denaturation by freezing. The characteristics of 26-kDa protein are analogous to the cold-regulated protein of the plants.

Thermal unfolding of the starch binding domain of Aspergillus niger glucoamylase

A fragment of the starch-binding domain (SBDF) of Aspergillus niger glucoamylase was prepared using recombinant DNA techniques, and its thermal unfolding was investigated by high-sensitivity differential scanning calorimetry (DSC). Thermal unfolding of SBDF was found to be reversible at pH 7 as expected from a DSC study of the whole enzyme molecule [Tanaka A. et al., J. Biochem., 117, 1024-1028 (1995)] but not reversible at acidic region. Numerical analysis of the DSC curves showed that the denaturation was two-state, and some of the SBDF molecules were oligomeric (average degree of oligomerization was 1.2) at pH 7. It was suggested that the denaturation temperature of SBDF was lower than that of the starch-binding domain in the whole enzyme molecule by about 4.5 degrees (decrease in the Gibbs energy change was 5.3 kJ mol-1) indicating a possibility that the starch-binding domain is stabilized by glycosylation of the domain itself, or by the highly glycosylated linker region.

Three-dimensional organization of collagen fibrils during corneal stromal wound healing after excimer laser keratectomy

PURPOSE

To investigate the structural changes in corneal stromal collagen fibrils after excimer laser keratectomy in relation to the degree of corneal haze.

SETTING

University of Tokyo Hospital, Tokyo, Japan.

METHODS

Corneal haze was quantitatively measured by analyzing the light scattering in Scheimpflug images of the corneas of white rabbits after excimer laser keratectomy. Collagen fibril structure was examined using scanning electron microscopy after chemical digestion with sodium hydroxide solution; the same specimens were examined by transmission electron microscopy after re-embedding.

RESULTS

Corneal haze reached a peak 4 weeks after excimer laser keratectomy and then gradually decreased. The collagen fibrils of the normal cornea were regularly arranged parallel to the surface of the cornea, with small interfibrillar distances. After excimer laser keratectomy, the arrangement was highly disordered, with increased interfibrillar distances. These structural changes were most prominent 4 weeks after excimer laser keratectomy.

CONCLUSION

The structural changes in the collagen fibrils of the corneal stroma, especially the increase in interfibrillar distances and the disordered arrangement, were associated with corneal haze after excimer laser keratectomy.

c-Myc gene single-strand binding protein-1, MSSP-1, suppresses transcription of alpha-smooth muscle actin gene in chicken visceral smooth muscle cells

The expression of alpha-smooth muscle actin is coordinately regulated by positive and negative cis- elements in the promoter region. Although cis -elements and trans -acting factors involved in the positive regulation of the alpha-smooth muscle (alpha-SM) actin gene have been well characterized, details of negative regulation remain unclear. In functional analyses using cultured gizzard smooth muscle cells, we identified a sequence ranging from -238 to -219 in the promoter region as a novel negative element. Mutation and deletion analyses further revealed that a sequence, TATCTTA (-228 to -222), is essential for negative regulation. Gel shift assay and Southwestern blotting indicated that a nuclear protein factor specifically interacts with single- or double-strand DNA including this sequence, and the protein factor displays a highly potent binding to the sense strand DNA. cDNA cloning and gel shift analysis using anti-MSSP-1 antibodies revealed that this protein factor is a chicken homolog of human MSSP-1 (c- myc gene single-strand binding protein-1). In fact, overexpression of MSSP-1 in cultured smooth muscle cells suppresses the promoter activity. These results suggest a novel function of MSSP-1 regarding the transcriptional regulation of alpha-sm actin gene.

[The early results of the minimally invasive direct coronary artery bypass (MIDCAB)]

The clinical experiences of 29 consecutive MIDCAB procedures performed at our institution between October, 1996, and October, 1997, were analyzed. Preoperative patient's characteristics were as follows; LAD single vessel disease: 25, double vessel disease: 1, triple vessel disease: 1, RC single vessel disease: 1, LMT lesion: 1, concomitant procedures: 2 (ASO: 1, AAA: 1). LITA harvesting was performed using the video-assisted thoracoscopy in initial 4 patients, and in last 10 patients we used the specially designed retractor THORALIFT (Autosuture Co., Ltd.) for harvesting LITA by direct vision. LAD was stabilized mechanically using the stabilizer when we performed the anastomosis in last 10 patients to enhance the quality of the anastomosis. The patency rate was 96%, but there were two patients (6%) who had the stenosis of the anastomosis site. Coronary artery occlusion time was 13.2 minutes in the mean. We also studied the hemodynamics of blood flow in LITA grafts with the aid of 7.5 MHz transthoracic duplex imaging in these MIDCAB patients and compared with the LITA grafts in conventional CABG performed in same periods. There were no statistical differences between the two groups about the graft flow and velocity. We conclude that MIDCAB would be an alternative procedure that can be performed with low risk and acceptable early results in selected patients.

[The cytotoxic effect of topical mitomycin C on the ciliary body in rabbits]

We evaluated the cytotoxic effects of mitomycin C (MMC) in rabbit eyes. A sponge soaked with MMC was placed on the bared sclera after conjunctival incision. We used four concentrations of MMC in distilled water: 0%, 0.04%, 0.1%, and 0.4%. MMC was applied to one eye only, with the fellow eye serving as control. The eyes were studied for intraocular pressure (IOP) and by fluorophotometry at 3, 7, 14, and 28 days of treatment. Eyes treated with 0.04% and 0.4% MMC were studied histologically at 3 and 28 days. All the MMC-treated eyes showed no significant changes regarding IOP (56 eyes) or fluorophotometric features (28 eyes) regarding aqueous humor dynamics and blood-aqueous barrier. Pathologic changes of the ciliary epithelium, including intracellular vacuoles and swelling of mitochondria, were more pronounced in eyes treated with 0.4% MMC than those treated with 0.04%. These changes were more manifest in areas inner to the site of application than in the opposite area. Topical application of 0.04% MMC thus showed no evident toxic effects on the function of the ciliary body and other pathological changes were minor.

Functional involvement of serum response factor in the transcriptional regulation of caldesmon gene

A 22-bp fragment including the CArG element (CArG1) is essential for the transcription of the caldesmon gene. In this study, we investigated the effects of serum response factor (SRF) on the functional regulation of caldesmon promoter in smooth muscle cells. Gel supershift assay revealed that SRF was one component of the CArG1-protein complex. Dominant-negative mutants of SRF suppressed the promoter activity of caldesmon, whereas wild-type SRF overcame this suppression. These results suggest that SRF functions as a core activating factor of the caldesmon promoter. Furthermore, fractionation of smooth muscle cells' nuclear extracts using DNA affinity paramagnetic particles suggests that SRF transactivates the caldesmon promoter in concert with additional factors in the flow-through fraction recruited to the CArG element.

[Functions of the transforming growth factor-beta superfamily in eyes]

One human body is composed of 6 x 10(13) cells, and eyes are also composed of many cells of different functions. The cellular functions and intercellular interaction are regulated by many regulators including cytokines and growth factors to maintain the homeostasis. The transforming growth factor-beta (TGF-beta) superfamily, a large family of multifunctional factors, regulates various cellular functions, including cellular proliferation, migration, differentiation, apoptosis and extracellular matrix production. The TGF-beta superfamily contains about 30 multifunctional factors, and is divided into several families according to the sequence homology. The TGF-beta family, the activin family, and bone morphogenic proteins belong to the TGF-beta superfamily. TGF-beta superfamily members transduce signals through type I and type II serine/threonine type transmembrane receptors. The signals are transduced from receptors through nuclei by Smad family members, which are phosphorylated by the activated type I receptors and translocate from cytoplasm into nuclei. TGF-beta family members and the TGF-beta superfamily receptor family are expressed in ocular tissues including the cornea, ciliary epithelium, lens epithelium, retina, and blood vessels. This observation suggests the importance of the TGF-beta superfamily in eyes. Smad family members (Smad 1, Smad 2, Smad 3 and Smad 4) are expressed in the cultured retinal pigmant epithelial cell line (D407), in which TGF-beta and activin A stimulate the translocation of Smad 2, but not Smad 1 into nuclei, whereas bone morphogenetic protein (BMP) stimulates that of Smad 1, but not Smad 2. TGF-beta superfamily members play important roles in the pathogenesis of retinal neovascularization and in the wound healing process of corneal tissue. TGF-beta inhibits the endothelial functions, but, stimulates angiogenesis in vivo. TGF-beta is involved in the formation of abnormal connective tissue in corneal wound healing. In these processes, many cytokines and growth factors are involved, interacting with each other and forming networks. It is mandatory to clarify the networks to investigate molecular pathogenesis and new therapeutic agents.

Smooth muscle cell phenotype-dependent transcriptional regulation of the alpha1 integrin gene

The expressional regulation of chicken alpha1 integrin in smooth muscle cells was studied. The alpha1 integrin mRNA was expressed developmentally and was distributed dominantly in vascular and visceral smooth muscles in chick embryos. In a primary culture of smooth muscle cells, alpha1 integrin expression was dramatically down-regulated during serum-induced dedifferentiation. Promoter analyses revealed that the 5'-upstream region (-516 to +281) was sufficient for transcriptional activation in differentiated smooth muscle cells but not in dedifferentiated smooth muscle cells or chick embryo fibroblasts. Like other alpha integrin promoters, the promoter region of the alpha1 integrin gene lacks TATA and CCAAT boxes and contains binding sites for AP1 and AP2. The essential difference from other alpha integrin promoters is the presence of a CArG box-like motif. Deletion and site-directed mutation analyses revealed that the CArG box-like motif was an essential cis-element for transcriptional activation in differentiated smooth muscle cells, whereas the binding sites for AP1 and AP2 were not. Using specific antibodies, a nuclear protein factor specifically bound to the CArG box-like motif was identified as serum response factor. These results indicate that alpha1 integrin expression in smooth muscle cells is regulated transcriptionally in a phenotype-dependent manner and that serum response factor binding plays a crucial role in this regulation.

Detection of canine pemphigus foliaceus autoantigen by immunoblotting

The antigens targeted by autoantibodies in sera from canine patients with pemphigus foliaceus (PF) were detected by indirect immunofluorescence and Western immunoblotting. The extracted proteins from canine keratinocytes cultured in high-calcium condition for 48 h after confluency and from bovine nose epidermis were used as antigens in Western blotting. Canine keratinocytes cultured in high-calcium condition showed fluorescent deposits in intercellular spaces by incubation with sera from both canine and human pemphigus patients. By Western blotting, eight out of 16 canine PF sera recognised 160 kDa protein. 85 kDa and 120 kDa proteins were also recognised by four to five canine PF sera, respectively. The 160 kDa band, recognised by eight canine PF sera, had an identical mobility to the protein identified by a human PF serum. These results suggested that the autoantibodies in sera from canine PF recognised the 160 kDa desmosomal proteins, which may correspond to the desmoglein 1.

GABAergic neurotransmission in rat taste buds: immunocytochemical study for GABA and GABA transporter subtypes

Gamma-aminobutyric acid (GABA) is known to be a candidate for the neurotransmitter involved in the sense of taste. We hereby studied GABA and its termination system, GABA transporters, in rat taste buds by immunocytochemical approaches. Immunoblot analysis of three GABA transporter subtypes (GAT1, GAT2 and GAT3) revealed that the immunoreactive bands of GAT2 and GAT3, but not GAT1, were detected in the tongue. GAT3-immunoreactive band was recognized only in the circumvallate papilla containing a large number of taste buds while GAT2-immunoreactive bands were seen in all areas of the tongue. GAT2 immunoreactivity appeared to be specifically in the nerve fibers beneath the lingual epithelium. Both GAT3 and GABA immunoreactivities were detected only in taste buds. A few GAT3-immunoreactive cells were found in a cross-section of each taste bud but most GAT3-immunoreactive cells were localized in the margin of the taste bud. GAT3 was predominantly concentrated in the distal portion of the GAT3-immunoreactive cells. In contrast, GABA-immunoreactive cells were seen more frequently within each taste bud and the immunoreactivity was distributed throughout the perikarya of the cells. These results suggest that the GABA-uptake system is present in the taste buds and the GABAergic neurotransmission involved in the sensation of taste is terminated by the uptake of GABA into certain taste cells via GAT3.

[Biochemical and molecular characterization of Salmonella serovar enteritidis phage type 4 isolated from food poisoning outbreaks in Tokyo]

Since 1989, outbreaks of Salmonella ser. Enteritidis (S. Enteritidis) food poisoning have dramatically increased in Tokyo, and a total of 31 outbreaks has been reported in 1989. Twenty-one of these 31 outbreaks were caused by S. Enteritidis PT34, but 8 outbreaks were caused by S. Enteritidis PT4. After 1990 instead of SE PT34, food poisoning due to PT4, which was a very common phage type in the UK, has increased in Tokyo. Between 1989 and 1995, there were 144 food poisoning outbreaks caused by S. Enteritidis, and 64 of these outbreaks were by due to S. Enteritidis PT4, which was one of the main phage types in Tokyo. To characterize these strains of phage type (PT) 4,293 isolates from patients, and vehicle foods, eggs and environment in Tokyo were examined for plasmid DNA profiles, acid productivity from glycols (propylene and ethylene) and antimicrobial resistance patterns. Plasmid DNA was extracted by Kado's method, and analyzed by agarose gel electrophoresis. The acid productivity from propylene glycol or ethylene glycol were tested using Barsicow medium with 1% propylene glycol or ethylene glycol. Antimicrobial susceptibility to AM, CP, TC, SM, KM, NA, ST, FOM and NFLX was tested by the K-B disc method. The strains of PT4 were further subdivided into 9 types by those epidemiologic marker analysis. The prevalent pattern of PT4 strains was type A plasmid profile carrying only one plasmid (60 kb) and there were 2 kinds of antibiograms. One was SM resistant, while the other was susceptible. A total of 56 (87.5%) of 64 outbreaks was found to have been caused by these types of S. Enteritidis. Several kinds of egg-related foods were suspected as the vehicles of transmission among 24 outbreaks. Especially, in 5 outbreaks, S. Enteritidis strains were isolated both from patients and suspected food which were cooked with egg. This strongly suggests that these foods may be the potential source of infection in S. Enteritidis PT4 outbreaks.

Purification and properties of an aminopeptidase from a protamine-degrading marine bacterium

A protamine-degrading marine bacterium was isolated from marine soil and identified as Aeromonas salmonicida subsp. based on its taxonomical characteristics. An alanine-specific aminopeptidase, called aminopeptidase K, from an extract of the strain was purified and characterized. The aminopeptidase K was purified about 80-fold by fractionation with ammonium sulfate and column chromatography on QA-52 cellulose, Phenyl Superose and Superose 12. The purified enzyme is composed of 6 subunits of 86 kDa with a molecular mass of 520 kDa according to gel filtration and SDS-PAGE. The N-terminal sequence of the enzyme was H.Gly-Gln-Gln-Pro-Gln-Ile-Lys-Try-Tyr-His-Asp-Tyr-Asp-Ala-Pro-Asp-Tyr-Ty r- Ile-Thr-. It is inhibited by monoiodoacetate, N-ethylmaleimide, and puromycin. The Michaelis constant (K(m)) and the maximal rate of hydrolysis (Vmax) were, respectively, 0.28 mM and 49.4 mumol/min/mg for the L-Ala-beta-naphthylamide substrate. The optimum pH and optimum temperature were 6.5 and 45 degrees C, respectively. The purified enzyme was highly specific to L-Ala-beta-naphthylamide.

[Evaluation of a latex agglutination method for detecting and characterizing verotoxin (VT) produced by Escherichia coli]

The detection of VT produced by Escherichia coli is very important for the identification of verotoxin-producing Escherichia coli (VTEC). The latex agglutination reagents (Denka Seiken Co. Ltd, Tokyo) which was developed to detect VT was compared with the vero cell bioassay or polymerase chain reaction method. A total 147 VT-positive strains (109 serotype O157:H 7/- and 38 non-O157 serotype) and 31 VT-negative strains which were isolated from human were investigated. In addition, a total of 79 VT-positive strains (14 serotype O157:H7/- and 65 non-O157 serotype) and 79 VT-negative strains which were isolated from animals were also examined. The latex agglutination assay for the human isolates showed the 100% sensitivity, specificity and agreement. The assay for the animal isolates showed 94.9% sensitivity, 100% specificity and 97.5% agreement. Although 4 of 8 strains isolated from swine which produce VT2 variant toxin (VT2e) failed in detecting verotoxin by latex agglutination assay, VT2e was not related to human infections. We conclude that this latex agglutination reagent is highly sensitive and specific for detecting and characterizing VT of E. coli. The method is reliable, easy to perform at any laboratories.

[Effects of topical corticosteroids on subepithelial haze after excimer laser corneal surgery--objective and quantitative method for evaluating haze]

To examine the effectiveness of topical corticosteroids in decreasing subepithelial haze induced by excimer laser keratectomy, we performed excimer laser keratectomy on 24 eyes of 12 albino rabbits using a scanning excimer laser system (EC-5000, NIDEK, Japan). Topical dexamethasone 0.1% was applied topically to 8 corneas after surgery (steroid group), but not to the others (control group). Slit-lamp biomicroscopic examination and objective measurement of scattered light from subepithelial haze were performed before and 2, 4, 8 and 12 weeks after surgery, the rabbits were killed after 2 or 12 weeks and the eyes were examined histologically. In both groups, densitometric values of scattered light intensity increased up to 4 weeks after surgery, and then decreased gradually. However, the values of the steroid group were larger than those of the control group at all stages, and the values of the steroid group at 12 weeks after surgery were similar to preoperative values. There was statistically significant difference in scattered light intensity between the two groups (p < 0.005). Two weeks after surgery, the corneas of the control group showed epithelial hyperplasia and a remarkable increase in activated keratocytes and subepithelial fibrous tissues. However, in the steroid group these light microscopic findings could not be observed. At 12 weeks after surgery, the corneas of the control group retained a small amount of activated keratocytes and fibrous tissues, and those of the steroid group were normal. This study suggests that a short course of topical corticosteroids may be very effective in decreasing subepithelial haze after excimer laser corneal surgery.

Ganglioside composition of the human cranial nerves, with special reference to pathophysiology of Miller Fisher syndrome

Total ganglioside fractions from the human cranial nerves purified on a Phenyl Sepharose column, were given mild alkaline treatment, after which their composition and amounts of lipid-bound sialic acid were determined by HPTLC-densitometry with resorcinol as the coloring reagent. The total amounts of lipid-bound sialic acid were 156.5 ng/mg of wet tissue in the Ist cranial nerve (olfactory tract) and 131.9 ng/mg in the IInd nerve, greater than the amounts in the other nerves (99.1-120.0 ng/mg). The Ist, IInd, and VIIIth nerves had GM4, but not LM1. It may reflect their histological feature of the central nervous system. The IIIrd, IVth, and VIth nerves, as well as the IInd, had significantly higher percentages of GQ1b (11.6-13.2%) than the other nerves (5.2-8.4%). The high proportion of GQ1b specific to these three cranial nerves involved in the ocular movement lends support to the role of serum anti-GQ1b antibody in the pathogenetic mechanisms of ophthalmoplegia in Miller Fisher syndrome and Guillain-Barré syndrome.

P21waf-1/cip-1/sdi-1 is expressed at G1 phase in primary culture of hepatocytes from old rats, presumably preventing the cells from entering the S phase of the cell cycle

To elucidate whether p21waf-1/cip-1/sdi-1 expression is associated with loss of growth potential of hepatocytes of old rats, we determined p21waf-1/cip-1/sdi-1 expression of hepatocytes from old (30 months) rats during the cell cycle in primary culture. A high level of expression of p21waf-1/cip-1/sdi-1 was detected at the G1 phase in old-rat hepatocytes, but after the S phase in young-rat hepatocytes. Consistently, the incidence of the cells positive for p21waf-1/cip-1/sdi-1 in nuclei before entering the S phase was significantly higher in old-rat hepatocytes than in young-rat hepatocytes. These results account for the loss of growth potential of old-rat hepatocytes in vitro and the marked retardation of regeneration of liver in old rats in vivo.

Expression of p21(waf-1/cip-1) is significantly induced in the livers of LEC rats with chronic liver injury

It is reported that hepatocytes isolated from LEC rats with chronic liver injury show reduced growth activity in primary culture. To elucidate the molecular basis of this phenomenon, we examined expression of p21(waf-1/ciP-1) and p27, cyclin-dependent kinase inhibitors, by northern blot analysis. The expression of p21(waf-1/cip-1 ) in the LEC rat liver was 3-fold higher than that of age-matched SD rat liver, while there was no significant difference in p27 expression level. Western blot analysis also revealed a significant increase in p21(waf-1/cip-1) in the nuclear matrix fraction of the LEC rat liver. Immunohistochemically, p21(waf-1/cip-1) was detected in the nuclei of normal LEC rat hepatocytes, but not in those of hepatocellular carcinoma cells, suggesting selective growth of neoplastic hepatocytes.

Phase-Dependent effects of transforming growth factor beta 1 on osteoblastic markers of human osteoblastic cell line sV-HFO during mineralization

A human osteoblastic cell line (SV-HFO) established in our laboratory expresses osteoblastic markers, including mineralization in vitro, in response to differentiation-inducing agents such as dexamethasone. In this study, we examined the effects of transforming growth factor beta 1 (TGF-beta 1) on the mineralization of SV-HFO cells and show that TGF-beta 1 inhibited the mineralization of the cells via down regulation of tetranectin and alkaline phosphatase without influencing other osteoblastic markers. To examine precisely the effects of TGF-beta 1 on the process of mineralization, we tentatively divided the whole process of mineralization into four phases: induced ALP activity (days 0-5), maximal ALP activity (days 5-10), early mineralization (days 10-15), and progressive mineralization (days 15-20). These inhibitory effects of TGF-beta 1 on the expression of tetranectin and alkaline phosphatase, like that on mineralization, were observed only when TGF-beta 1 was applied in the early phase of the process of mineralization. On the other hand, the other osteoblastic markers were not influenced by treatment with TGF-beta 1. These results suggest that TGF-beta 1 may inhibit mineralization of osteoblasts by the downregulation of tetranectin and alkaline phosphatase expression in the early phase. Thus, TGF-beta 1 has phase-dependent effects on a human osteoblastic cell line during the process of mineralization.

Abnormal accumulation of copper in LEC rat liver induces expression of p53 and nuclear matrix-bound p21(waf 1/cip 1)

The LEC rat is an inbred mutant strain which spontaneously develops liver injury and subsequent liver cancer. Liver injury in LEC rats has recently been shown to be closely related to abnormal copper accumulation in the liver. Previously, we reported that LEC rat hepatocytes lose their growth potential, probably allowing selective growth of preneoplastic cells. In this study, to elucidate the effects of copper accumulation on the growth activity of LEC rat hepatocytes, we examined the growth activity and the expression of p53 and p21(waf 1/cip 1) in the livers of LEC rats fed on either a control or a low-copper diet. Potential for cell proliferation of hepatocytes obtained from normal diet fed LEC rats was almost comparable to that of the cells from age-matched Sprague-Dawley (SD) rats. Northern blot analysis showed that the expression of p53 and p21(waf 1/cip 1) was significantly high in the livers of LEC rats fed a control diet, while the expression of p53 and p21(waf 1/cip 1) in the LEC rats fed a low-copper diet was as low as that of SD rat livers. Western blot analysis consistently showed that the amount of p21(waf 1/cip 1) bound to the nuclear matrix scaffold of the LEC rat liver was reduced by feeding a low-copper diet. These findings suggest that abnormal accumulation of copper induced the expression of p53 and p21(waf 1/cip 1), resulting in the inhibition of cell proliferation of LEC rat hepatocytes.

[NO2 inhalation in two smokers and two non-smokers]

Four healthy men were exposed to an anti-rust substance in a stainless steel tank. Acute respiratory failure developed in two of them, both non-smokers. Their chest roentgenograms revealed marked infiltration, which suggested pulmonary edema due to the inhalation of NO2 and hydrogen fluoride. These two patients recovered from respiratory distress within several days. However, small airway disease was still evident one year later. The other two, who were smokers, had only mild respiratory symptoms. These cases indicate that smoking may reduce the sensitivity to NO2. Further study is needed to elucidate the relationship between smoking and the severity of responses to NO2 inhalation.

[Detection of the trh gene in Vibrio parahaemolyticus isolated from overseas travellers' diarrhea and their biochemical characteristics]

A total of 478 Vibrio parahaemolyticus strains isolated from overseas travellers' diarrhea during the last 7 years of 1989 to 1995 were examined for the production of Kanagawa hemolysin by reversed passive latex agglutination (RPLA) test. Three hundred-seventy (77.4%) out of 478 strains were positive for Kanagawa hemolysin, whereas 108 strains were weakly positive or negative. For those Kanagawa hemolysin-weakly positive or negative strains, the tdh and trh genes associated with the production of TDH (thermostable direct hemolysin) and TRH (TDH-related hemolysin), respectively, were studied by the polymerase chain reaction method. The trh gene was detected in 98 (90.7%) out of 108 strains. In 35 strains belonging to 13 serotypes such as O3: K6, O1:K33, O3:K59, the trh gene alone was detected. On the other hand, both trh and tdh genes were detected in 63 strains of 17 serotypes including O1:K69, O3:K72, O6:K46. Among the strains of 4 serotypes including O1:K56, O1:KUT, O3:KUT and O5:KUT, two types of the trh positive alone and the trh and tdh positive were observed. Of interest, all of the 98 trh-positive strains were positive for the urease hydrolysis, whereas all Kanagawa hemolysin-positive strains were not. Furthermore, the strains of serotype O6:K18 (4 strains) were positive for the fermentation of dulcitol, and the strains of serotype O1:K1 (5 strains) were indole negative. These characteristics of the strains were completely different from those of typical V. parahaemolyticus strains.

NF-kappa B is induced in the nuclei of cultured rat aortic smooth muscle cells by stimulation of various growth factors

We investigated whether induction of transcription factor NF-kappa B is involved in the proliferation of cultured rat aortic smooth muscle cell using electrophoretic mobility shift assay and immunocytochemistry. NF-kappa B was induced in the nucleus in a dose-dependent manner when the smooth muscle cells were stimulated by various growth factors such as PDGF-BB, bFGF, EGF and IGF-1, but not growth inhibitors such as TGF-beta and IFN-gamma. Among growth factors, PDGF-BB and bFGF, more potent growth stimulators, induced higher kappa B binding activity than EGF or IGF-1. These evidences were also supported by the results obtained with immunocytochemistry. Immunocytochemistry also showed that the induced NF-kappa B contained p50 and p65. These results suggest that NF-kappa B induction may be involved in the proliferation of vascular smooth muscle cell.

[Characterization of Salmonella ser. enteritidis phage type 34 isolated from food poisoning outbreaks in Tokyo by epidemiological makers]

Since 1989, outbreaks of Salmonella ser. Enteritidis food poisoning has dramatically increased in Tokyo, and a total of 95 outbreaks has been reported between 1989 and 1993. As the results of examination of phage type by the method of Ward, et al., strains isolated from 31 (32.6%) of 95 outbreaks were phage type 34 which is a very rare type in Europe and America. To characterize these unique strains of phage type (PT) 34, 302 isolates obtained from patients and vehicle foods of the outbreaks, eggs and environments in Tokyo were examined for plasmid DNA profiles and antimicrobial resistance patterns. Plasmid DNA was extracted by the Kado's method, and analysed by agalose gel electrophoresis. Antimicrobial susceptibility was tested for CP, TC, SM, KM, ABPC, NA, SXT, FOM and NFLX by the K-B disc method. The strains of PT 34 were further subdivided to 4 types by plasmid profile and antibiogram. The prevalent pattern of PT 34 strains was type plasmid profile which carried 2 different plasmids (> 250 and 60 kb) and was streptomysin-resistant. A total of 28 (90.3%) of 31 outbreaks were found to be caused by this specific type of Salmonella ser. Enteritidis. Several kinds of egg-related foods were suspected for the vehicles of transmission among 12 outbreaks. Especially, in 5 outbreaks, this specific type (type B plasmid profile and streptomysin resistant) of Salmonella ser. Enteritidis strains were isolated both from patients and incriminated food which were cooked with eggs. The phase type of Salmonella ser. Enteritidis strains isolated from raw egg and poultry or environmental specimens from poultry farm showed that the prevailing phage types were almost the same as those of foods poisoning outbreaks. This strongly suggests that these foods may be considered as a source of infection in Salmonella ser. Enteritidis outbreaks.

Conversion of glutathione into cadystins and their analogs catalyzed by carboxypeptidase Y

Cadystins induced in a fission yeast treated with Cd2+ are the higher homologs of glutathione. In the present work, glutathione was incubated with Carboxypeptidase Y at a high substrate concentration. The reaction afforded not only the degraded product, but also cadystins and their analogs. A possible transformation pathway for glutathione by this enzyme is proposed.

Cervical spondylotic radiculopathy involving two adjacent nerve roots. Anterior decompression through a single level intervertebral approach

We describe a single level intervertebral approach to decompress two adjacent involved nerve roots in cases of cervical spondylosis. The operation was undertaken in 4 patients. We carried out discectomy, partial excision of the vertebral body with removal of the anteromedial part of the pedicles, removal of osteophytes and excision of the posterior longitudinal ligament, followed by an anterior interbody fusion. Fusion was achieved with the spine in normal lordosis and without complications. Pain and motor weakness was relieved in every case. This procedure can maintain movement at one additional disc level and has a better fusion rate than multilevel inter-body fusion.

The role of cell adhesion molecules in allograft rejection after penetrating keratoplasty in mice. Clinical and immunohistochemical study

BACKGROUND

It has been reported that adhesion molecules play an important role in immunological rejection after organ transplantation. In the present study, we examined the role of ICAM-1/ LFA-1 adhesion molecules in corneal allograft rejection and evaluated the immunological specificity of monoclonal antibodies (mAbs) in preventing allograft rejection in mice.

METHODS

The allografted mice were intraperitoneally injected with 100 micrograms/day of the following mAbs: a control mAb, anti-ICAM-1 mAb, anti-LFA-1 mAb, or a mixture of anti-ICAM-1 and anti-LFA-1 mAbs from 1 day before to 7 days after surgery. The expression of ICAM-1 and LFA-1 molecules in the grafted cornea was studied immunohistochemically. The corneas from a syngeneic donor or a third-party strain were transplanted 4 weeks after the initial keratoplasty onto the mice treated with both anti-ICAM-1 and anti-LFA-1 mAbs.

RESULTS

The allografts treated with anti-LFA-1 mAb alone or both anti-ICAM-1 and anti-LFA-1 mAbs remained transparent for more than 2 weeks, and the survival rate at 8 weeks was 40% in both groups. ICAM-1 was expressed on the mononuclear cells, keratocytes and endothelial cells in the allografts without treatment. The second corneal grafts syngeneic to the initial donor remained transparent at 2 weeks, whereas those from the third party were rejected.

CONCLUSIONS

ICAM-1 and LFA-1 adhesion molecules play a crucial role in the pathophysiology of corneal transplant rejection. The immunosuppressive effects of anti-ICAM-1 and anti-LFA-1 mAbs are highly allospecific. The administration of mAbs to the adhesion molecules represents a new means of suppressing allograft rejection after penetrating keratoplasty.

Effect of substrate on indirect immunofluorescence test for canine pemphigus foliaceus

The effect of substrate on indirect immunofluorescence (IIF) tests for the detection of circulating autoantibodies was studied by examining sera from 14 canine pemphigus foliaceus patients, six sera with non-pemphigus dermatoses and ten normal dog sera against five different substrates from three species. These substrates included bovine esophagus, bovine nose, bovine tongue, monkey esophagus, and canine nose skin. Nine out of 14 (64.3%) sera from patients with canine pemphigus foliaceus showed intercellular space staining by indirect immunofluorescence using bovine esophagus as substrate. However, sera from nonpemphigus dermatoses and normal dog did not react with bovine esophagus. In other substrates, only bovine tongue showed 1/8 (12.5%) positive reaction at the intercellular space by sera from canine pemphigus foliaceus. Dog nose skin showed the intercellular space staining against ten of ten (100%) normal dog serum. Monkey esophagus showed the fluorescent deposit at the intercellular space in four of nine (44.4%) of pemphigus foliacues dog sera, however, four of ten (40%) of normal dog sera revealed nonspecificity intercellular staining. These results indicate that the sensitivity and the specifity of IIF test in canine pemphigus foliaceus depend on the substrate. The best substrate for detecting circulating autoantibody in canine pemphigus foliaceus patients among five different substrates was bovine esophagus because of its sensitivity and high specificity. The diagnosis of canine pemphigus foliaceus should be made on the basis of a combination of clinical signs, histopathology, direct immunofluorescence, and the detection of circulating autoantibody.

Expression of TGF-beta type I and type II receptors in rat eyes

Transforming growth factor beta (TGF-beta) transduces signals through mediation of type I and type II serine/threonine kinase receptors. The expression of TGF-beta type I (T beta R-I) and II (T beta R-II) receptors in rat eyes was investigated immunohistochemically. T beta R-I and T beta R-II immunoreactivity was detected in corneal and conjunctival epithelial cells, corneal endothelial cells, ciliary epithelial cells, lens epithelial cells, retinal pigment epithelial cells, and choroidal vessels. This co-expression of T beta R-I and T beta R-II indicates that the above cells respond to TGF-beta and, because TGF-beta is reported to be produced in ocular tissues, that it may have important autocrine and/or paracrine roles in the growth and metabolism of ocular tissues in situ.

Histopathology of the liver in non-cirrhotic portal hypertension of unknown aetiology

Non-cirrhotic, long-standing portal hypertension of unknown aetiology is being re-evaluated histopathologically and clinically. In this study, we examined 107 livers with this condition (92 wedge biopsy and 15 autopsy specimens) from five institutions in Japan. These cases were histologically categorized into four groups: idiopathic portal hypertension (66 cases), nodular regenerative hyperplasia (14 cases), partial nodular transformation (two cases), and incomplete septal cirrhosis (25 cases). These four groups shared several histological features: dense portal fibrosis with portal venous obliteration and intralobular slender fibrosis. In addition, the histopathological features characteristic of one group were also found to a mild degree in other groups. The histopathological lesions preceding portal venous obliteration remain speculative. However, the portal venous obliteration may be responsible for the occurrence of sustained portal hypertension and several of the pathological changes in these livers. It seems likely that idiopathic portal hypertension, nodular regenerative hyperplasia, partial nodular transformation and incomplete septal cirrhosis comprise a family of non-cirrhotic, long-standing portal hypertension in Japan, and the histological differences between them may reflect chronological progression of a single disease.