Assessment of potential macular function using a color saturation discrimination test in eyes with cataract

PURPOSE

To study the efficacy of a color saturation discrimination test (CSDT) in assessing potential macular function in eyes with cataract.

SETTING

Yamanashi Medical University and Nirasaki City Hospital, Yamanashi, Japan.

METHODS

In this prospective study of 200 consecutive eyes with cataract, the thresholds of color saturation discrimination on 6 hues were measured with the CSDT. The CSDT program was run on a personal computer and cathode-ray tube color monitor. The preoperative CSDT scores and postoperative visual acuities were compared. In addition, preoperative laser interferometry (LI) and postoperative CSDT were performed on selected patients and the results compared with their preoperative CSDT results.

RESULTS

Patients who had a CSDT score of 11 or more had a significantly lower postoperative visual acuity (P < .0001). The prevalence of neuroretinal abnormality postoperatively increased with the preoperative CSDT score. The CSDT score was not correlated with preoperative visual acuity (P = 1409). Cataract severity had little influence on the CSDT score. The preoperative results of the CSDT and Ll were correlated with the postoperative acuity, with the correlation coefficient being stronger with the CSDT (r = -0.338 and 0.276 for CSDT and Ll, respectively).

CONCLUSION

The CSDT was effective in evaluating neuroretinal pathology and predicting postoperative acuity.

Progression of defects in the central 10-degree visual field of patients with retinitis pigmentosa and choroideremia

PURPOSE

To determine the progression of defects in the central 10-degree visual field in patients with retinitis pigmentosa and choroideremia by means of univariate linear regression with respect to the mean deviation.

METHODS

In a retrospective study, results of automated static perimetry in the central 10-degree visual field were reviewed for patients with retinitis pigmentosa and choroideremia. Univariate linear regression of mean deviation was undertaken for each eye that had field data from at least five tests in addition to the prior static perimetric experience during a period of 3.5 years or more. Data from 30 eyes of 16 patients fulfilled eligibility requirements; the mean number of fields was 5.8 (range, five to 10) and the mean follow-up period was 64 months (range, 42 to 97 months). Eyes were classified as progressive if the regression coefficient was negative and significantly different from zero, with a P value of less than .05.

RESULTS

Among 14 patients in whom both eyes were eligible for univariate linear regression analysis, a statistically significant progression was demonstrated in both eyes in four patients, only in one eye in five patients, and in neither eye in five patients. One of two patients, in whom only one eye was eligible for the study, showed significant progression in the eye. Overall, 14 (47%) of 30 eyes showed statistically significant progression with respect to the mean deviation. No eye showed significant improvement.

CONCLUSIONS

Automated static perimetry of the central 10-degree visual field measured approximately once or twice a year demonstrated the progressive nature of the disease with the use of univariate linear regression of mean deviation in 47% of eyes with retinitis pigmentosa and choroideremia during the follow-up period of 3.5 years or more. These results may be useful in understanding the clinical course of the diseases and counseling patients.

Plasminogen activator inhibitor 1 in central serous chorioretinopathy

PURPOSE

To describe the plasma level of plasminogen activator inhibitor 1, the major antifibrinolytic agent, in eyes with central serous chorioretinopathy, in which choroidal thrombosis is suspected as the underlying condition based on the findings of choroidal hyperpermeability in indocyanine green angiograms.

METHODS

Plasminogen activator inhibitor 1 concentrations in the plasma of 17 patients with central serous chorioretinopathy were measured by enzyme-linked immunosorbent assay and compared with those in 12 age-matched normal volunteers.

RESULTS

The plasma levels of plasminogen activator inhibitor 1 in patients with central serous chorioretinopathy (range, 25 to 439 ng/ml; median, 87 ng/ml) were significantly increased compared with those in normal volunteers (range, 7 to 84 ng/ml; median, 36 ng/ml) (P = .0013, Mann-Whitney U test).

CONCLUSION

Increased plasminogen activator inhibitor 1 concentrations in patients with central serous chorioretinopathy support the hypothesis that the choroidal hyperpermeability disclosed by indocyanine green angiography is caused from impaired fibrinolysis and the resulting thrombotic occlusion in the choroidal veins.

Effects of 3alpha- and 3beta-galactosylated alpha-galactosylceramides on the immune system

We compared effects of alpha-galactosylceramide (alpha-GalCer) and its 3alpha- or 3beta-galactosylated derivatives on the proliferation of murine spleen cells. The 3alpha-galactosylated alpha-GalCer showed stronger proliferative response than the parental alpha-GalCer, but the 3beta-galactosylated alpha-GalCer possessed weaker activity than the alpha-GalCer. In addition, alpha-Gal-3-Cer did not show immunostimulatory activity.

Optical coherence tomography of idiopathic polypoidal choroidal vasculopathy

PURPOSE

To document and study the cross-sectional structures of polypoidal elements using optical coherence tomography in eyes with idiopathic polypoidal choroidal vasculopathy.

METHODS

Optical coherence tomography images of two eyes with idiopathic polypoidal choroidal vasculopathy were correlated with slit-lamp biomicroscopic findings, fundus photographs, fluorescein angiograms, and indocyanine green angiograms.

RESULTS

Cross-sectional optical coherence tomographic images of retinochoroidal structures showed prominent anterior protrusion of the orange subretinal mass corresponding to the polypoidal structure in the indocyanine green angiogram. Hemorrhagic detachment of the retinal pigment epithelium was contiguous with the cone-shaped nodule beneath the retinal pigment epithelium in one eye, and an apparent discontinuity was observed in the highly reflective layer that delineates the polypoidal structure.

CONCLUSIONS

Some of the polypoidal structures in eyes with idiopathic polypoidal choroidal vasculopathy are anteriorly protruding lesions in the inner choroid that may cause serosanguineous detachment of the retinal pigment epithelium through damage of the overlying Bruch membrane, retinal pigment epithelium, and the adhesion between them. Cross-sectional optical coherence tomographic images may increase understanding of the pathophysiology of idiopathic polypoidal choroidal vasculopathy.

Contribution of cytokines on the suppression of lung metastasis

Weekly injection of a protein-bound polysaccharide PSK in mice with Lewis Lung Cancer (LLC) significantly decreased the number of lung metastatic foci concomitant with enhancement of cytostatic activity in the bronchoalveolar lavage (BAL) cells. These effects were more marked when the agent was given intratracheally, inducing a larger number of pulmonary macrophages, lymphocytes and neutrophils concomitant with increases in BAL tumor necrosis factor-alpha (TNF-alpha), mouse inflammatory protein-alpha (MIP-1alpha), mouse inflammatory protein-beta (MIP-1beta), interleukin-1alpha (IL-1alpha) and interleukin-6 (IL-6), but not interleukin-2 (IL-2) and interleukin-4 (IL-4). Pre-treatment with anti TNF-alpha antibody reduced these effects. The time course and production of PSK-induced cytokines were similar between the tumor-bearing mice and control mice. BAL neutrophils in mice with LLC showed a tendency toward acceleration of O2- production compared with circulating neutrophils. Pulmonary macrophage phagocytosis was also significantly higher in the LLC mice. These results suggest that enhancement of cytostasis appears to be induced by activation and/or improvement of function in inflammatory and immune cells through cytokines under immunomodulator treatment in lung metastasis, possibly via a TNF-alpha-dependent mechanism.

Clonal expansion of CD4+ TCRbetabeta+ T cells in TCR alpha-chain- deficient mice by gut-derived antigens

A population of CD4+ alpha-beta+ T cells increases in the mucosal and peripheral lymphoid tissues of TCRalpha-chain-deficient mice with inflammatory bowel disease. The alpha-beta+ T cells, which produce predominantly IL-4, mediate the proliferation of colonic epithelial crypts and the infiltration of large numbers of IgA-producing plasma cells into the lamina propria of the colon. To examine whether enteric Ags were recognized by a population of monoclonal alpha-beta+ T cells leading to the intestinal inflammation, we examined the usage and clonotypes of TCR expressed by the alpha-beta+ T cells in TCRalpha-chain-deficient mice with inflammatory bowel disease. Analyses of immunoprecipitates by two dimensional electrophoresis and single-cell RT-PCR revealed that TCR of the alpha-beta+ T cells was a homodimer of beta-chains that was capable of recognizing luminal bacterial Ags. PCR single-strand conformation polymorphism analysis of TCR Vbeta transcripts revealed monoclonal accumulation of the alpha-beta+ T cells in the colonic lamina propria of the diseased mice. DNA sequencing revealed the accumulation of the alpha-beta+ T cells with the same CDR3 sequences in the colon. These findings suggest that the pathogenic CD4+ alpha-beta+ T cells expressing a homodimeric form of the TCRbeta-chains can be clonally expanded upon the stimulation with gut-derived Ags.

Deficiency of IL-5 receptor alpha-chain selectively influences the development of the common mucosal immune system independent IgA-producing B-1 cell in mucosa-associated tissues

Deletion of IL-5R alpha-chain (IL-5R alpha-/-) selectively influenced the mucosal IgA responses in vivo. While levels of IgA in mucosal secretions were more reduced in IL-5R alpha-/- mice than in wild-type mice, the levels of IgA in serum were not changed. The frequency of IgA-producing cells was reduced in mucosal effector sites (e.g., intestinal lamina propria and nasal passage), but not in inductive sites such as Payer's patches and nasal-associated lymphoreticular tissues in IL-5R alpha-/- mice. IgA-committed (surface IgA+; sIgA+) B-1 cells mainly resided in mucosal effector tissues, while conventional sIgA+ B (B-2) cells formed in mucosal inductive sites of wild-type mice. In contrast, in the effector tissue of IL-5R alpha-/- mice, sIgA+ B-1 cells, but not sIgA+ B-2 cells in the inductive site, were significantly reduced. IL-5R alpha was more expressed on sIgA+ B-1 cells than was IL-6R, while both IL-5R alpha and IL-6R were expressed on sIgA+ B-2 cells in wild-type mice. sIgA+ B-1 cells produced high levels of IgA with rIL-5 rather than of rIL-6 in vitro. Taken together, the findings suggest that the IL-5/IL-5R signaling pathway is critically important for the development of common mucosal immune system independent sIgA+ B-1 cell in mucosal effector tissues in vivo.

Nd:YAG laser photodisruption for preretinal hemorrhage due to retinal macroaneurysm

PURPOSE

To document the clinical course of Nd:YAG laser photodisruption for eyes with preretinal hemorrhage following rupture of a retinal macroaneurysm.

METHODS

We reviewed six eyes of five patients with preretinal hemorrhage due to retinal macroaneurysm that received Nd:YAG laser photodisruption. Nd:YAG laser created a focal opening in the anterior surface of the preretinal hemorrhage, permitting the blood to enter the vitreous cavity where it would be absorbed more rapidly.

RESULTS

Three eyes showed both subhyaloid hemorrhage, which was resorbed without treatment within 2 months, and hemorrhagic detachment of the internal limiting membrane (ILM), which required Nd:YAG laser photodisruption. All eyes showed disappearance of the preretinal hemorrhage and improvement of vision within 1 week of Nd:YAG laser photodisruption. Visual recovery was less prominent in eyes associated with subretinal macular hemorrhage.

CONCLUSION

Preretinal hemorrhage due to a ruptured retinal macroaneurysm could be dispersed into the vitreous cavity with Nd:YAG laser photodisruption. It should be considered in the decision of Nd:YAG laser photodisruption that the visual increment may be limited in eyes that also have subretinal hemorrhage in the macula and that the hemorrhage beneath the ILM tends to remain longer than the subhyaloid hemorrhage.

Orally administered cholera toxin prevents murine intestinal T cells from staphylococcal enterotoxin B-induced anergy

BACKGROUND & AIMS

Cholera toxin (CT) has been shown to be a strong mucosal adjuvant for the induction of antigen-specific secretory immunoglobulin A (IgA). The mechanism of adjuvant activity of CT is still unknown. The aim of this study was to examine the immunomodulatory function of CT on mucosal T cells using staphylococcal enterotoxin B (SEB) as coadministered oral antigen, because SEB has been shown to directly regulate alpha beta T-cell responses.

METHODS

C3H/HeN mice were orally or systemically immunized with SEB and/or CT. The levels of SEB-specific antibodies and frequencies of CD4(+)Vbeta8(+) T cells were analyzed. SEB-specific T-cell proliferation and cytokine production were also determined.

RESULTS

Neither SEB-specific IgA nor IgG antibodies were induced in feces when SEB was administered alone. This was a result of the clonal deletion and partial unresponsiveness of CD4(+)Vbeta8(+)T cells in Peyer's patches. On the other hand, SEB-specific antibodies were induced by oral immunization with SEB and CT. Although some degree of clonal deletion was induced by oral immunization with SEB and CT, coadministered CT prevented the induction of anergy for CD4(+)Vbeta8(+) T cells in Peyer's patches.

CONCLUSIONS

CT is a powerful immunomodulatory molecule that prevents mucosal T cells from SEB-induced anergy.

Evaluation of the PyloriTek test for detection of Helicobacter pylori infection in cases with and without eradication therapy

OBJECTIVE

The accuracy of the PyloriTek test (a 1-h rapid urease test) used after eradication therapy of Helicobacter pylori (H. pylori) has not been well clarified. This study was done to evaluate the accuracy of the PyloriTek test results for cases with and without eradication therapy, using culture and histology as gold standard methods, and to establish the suitable timing of the PyloriTek test after eradication treatment.

METHODS

One hundred sixty-three patients undergoing upper endoscopy were randomly selected; 100 patients had not received eradication therapy and 63 had. Three biopsy specimens each were obtained from the gastric antrum and the body for examination by PyloriTek, culture, and histology. The absence of H. pylori was established with negative results from both culture and histology.

RESULTS

In cases without eradication therapy, PyloriTek, correctly identified 66 of 67 H. pylori-positive cases and 30 of 33 H. pylori-negative cases, yielding 98.5% sensitivity and 90.9% specificity. In cases with eradication therapy, PyloriTek gave correct diagnoses in 10 of 17 H. pylori-positive cases and in 45 of 46 H. pylori-negative cases, for 58.8% sensitivity and 97.8% specificity. However, when PyloriTek was used more than 4 months after the end of eradication therapy, both the sensitivity and the specificity increased to 100%.

CONCLUSION

Considering time and cost, the use of PyloriTek alone may be satisfactory for detecting H. pylori infection in cases without eradication therapy. When patients are examined more than 4 months after intervention, the use of PyloriTek alone may be sufficient for correctly diagnosing H. pylori infections.

Effects of airway inflammation on cough response in the guinea pig

We have developed a guinea pig model for cough related to allergic airway inflammation. Unanesthetized animals were exposed to capsaicin aerosols for 10 min, and cough frequency was counted during this period. The cough evaluation was performed by the following three methods: visual observation, acoustic analysis, and monitoring of pressure changes in the body chamber. These analyses clearly differentiated a cough from a sneeze. To elucidate the relationship between cough response and airway inflammation, animals were immunosensitized and multiple challenged. Sensitized guinea pigs presented no specific changes microscopically, but multiple-challenged animals showed an increased infiltration of inflammatory cells into the airway. Cough number in response to capsaicin increased significantly from 4.7 +/- 1.4 coughs/10 min in normal animals to 10.6 +/- 2.0 coughs/10 min in sensitized animals and further to 22.8 +/- 1.3 coughs/10 min in multiple-challenged animals. This augmented cough frequency was significantly inhibited by the inhalation of tachykinin-receptor antagonists and by oral ingestion, but not inhalation, of codeine phosphate. The results suggest that airway inflammation potentiates an elevation of cough sensitivity in this model.

Thrombin-antithrombin III complex in acute retinal vein occlusion

PURPOSE

To determine whether quantitative differences in systemic hypercoagulable state could be identified among patients with retinal vein occlusion at various sites of occlusion.

METHODS

The value of thrombin-antithrombin III complex was determined in 57 patients with retinal vein occlusion within 1 month after the subjective onset of retinal vein occlusion and in 15 age-matched normal controls.

RESULTS

Levels of log thrombin-antithrombin III complex were significantly higher in the patients with proximal retinal vein occlusion in which the occlusion site is at the optic disc (mean +/- SD, 0.493 +/- 0.389) than in those with distal retinal vein occlusion in which the occlusion site is away from the optic disc (0.312 +/- 0.150, P = .025) and in the normal controls (0.294 +/- 0.151, P = .020). There was no significant difference between the distal retinal vein occlusion and the normal controls (P = .720). More patients with proximal retinal vein occlusion showed elevated thrombin-antithrombin III complex values more than 3.9 ng/ml than those with distal retinal vein occlusion (8/29 vs 1/28, P = .025). Of nine patients showing an initial value of thrombin-antithrombin III complex of more than 3.9 ng/ml, repeated measurements were obtained in eight patients, who showed reduced value of thrombin-antithrombin III complex in the normal range in several months.

CONCLUSIONS

A systemic hypercoagulable state, which could be demonstrated with the elevation of thrombin-antithrombin III complex value, may contribute more to the development of retinal vein occlusion with thrombus at or near the trunk of the central retinal vein than those with thrombus at branch veins away from the optic disc in the retina.

Evaluation of the PyloriTek test for detection of Helicobacter pylori infection in cases with and without eradication therapy

OBJECTIVE

The accuracy of the PyloriTek test (a 1-h rapid urease test) used after eradication therapy of Helicobacter pylori (H. pylori) has not been well clarified. This study was done to evaluate the accuracy of the PyloriTek test results for cases with and without eradication therapy, using culture and histology as gold standard methods, and to establish the suitable timing of the PyloriTek test after eradication treatment.

METHODS

One hundred sixty-three patients undergoing upper endoscopy were randomly selected; 100 patients had not received eradication therapy and 63 had. Three biopsy specimens each were obtained from the gastric antrum and the body for examination by PyloriTek, culture, and histology. The absence of H. pylori was established with negative results from both culture and histology.

RESULTS

In cases without eradication therapy, PyloriTek, correctly identified 66 of 67 H. pylori-positive cases and 30 of 33 H. pylori-negative cases, yielding 98.5% sensitivity and 90.9% specificity. In cases with eradication therapy, PyloriTek gave correct diagnoses in 10 of 17 H. pylori-positive cases and in 45 of 46 H. pylori-negative cases, for 58.8% sensitivity and 97.8% specificity. However, when PyloriTek was used more than 4 months after the end of eradication therapy, both the sensitivity and the specificity increased to 100%.

CONCLUSION

Considering time and cost, the use of PyloriTek alone may be satisfactory for detecting H. pylori infection in cases without eradication therapy. When patients are examined more than 4 months after intervention, the use of PyloriTek alone may be sufficient for correctly diagnosing H. pylori infections.

Deletion of bone marrow stromal cell antigen-1 (CD157) gene impaired systemic thymus independent-2 antigen-induced IgG3 and mucosal TD antigen-elicited IgA responses

Bone marrow stromal cell Ag-1 (BST-1; CD157)-deficient mice were generated to examine the immunologic roles of the molecule in vivo. In BST-1(-/-) mice, the development of peritoneal B-1 cells was delayed, and CD38(low/-) B-lineage cells were increased in the bone marrow and spleen. Partial impairment of thymus-independent (TI-2) and thymus-dependent (TD) Ag-specific immune responses was noted in the systemic and mucosal compartments of BST-1(-/-) mice, respectively. Although serum Ig levels as well as TD and TI-1 Ag-specific systemic immune responses were normal, the TI-2 Ag-induced IgG3 response was selectively impaired. Oral immunization of BST-1(-/-) mice with cholera toxin, a potent TD Ag for the induction of IgA response, resulted in the poor production of Ag-specific Abs at the intestinal mucosa accompanied by the reduced number of Ag-specific IgA-producing cells in the lamina propria. These results indicate that BST-1 has roles in B cell development and Ab production in vivo.

Nasal immune system: distinctive Th0 and Th1/Th2 type environments in murine nasal-associated lymphoid tissues and nasal passage, respectively

The nasal mucosa, an important arm of the mucosal immune system, is the first site of contact with inhaled antigens to induce an IgA response. A major aim of this study was to characterize the Th1 and Th2 cytokine expression of mucosal T cells residing in nasal-associated lymphoid tissue (NALT) and nasal passages (NP) as IgA inductive and effector sites, respectively, at the transcription and cellular levels. An application of single-cell reverse transcription-PCR for analysis of Th1 (IFN-gamma) and Th2 (IL-4 and IL-6) cytokine-specific mRNA revealed the presence of CD4+ T cells with a Th0 profile in NALT, while high numbers of Th2 cytokine-specific mRNA expressed by CD4+ T cells were noted in NP followed by Th1-type cells. NALT CD3+ CD4+ T cells of Th0 type have the capacity to become Th1- and/or Th2-type cells since their activation via the TCR-CD3 complex resulted in the expression of an array of Th1 and Th2 cytokines. CD3+ CD4+ T cells from NP, but not NALT, provide a helper function for the induction of antibody-forming cells including IgA isotype in B cell cultures. These findings suggest that NALT is characterized by a Th0 environment which can gain a Th1 and/or Th2 phenotype. In contrast, NP is considered to be a Th2 dominant site with some Th1 cells that can support the induction of IgA-producing cells.

Expression and characterization of a very low density lipoprotein receptor variant lacking the O-linked sugar region generated by alternative splicing

The very low density lipoprotein receptor (VLDLR) gene contains an exon encoding a region of clustered serine and threonine residues immediately outside the membrane-spanning sequence, and this region has been proposed to be the site of clustered O-linked carbohydrate chains. Two forms of VLDLR transcripts, with and without the O-linked sugar region, are generated through alternative splicing. Reverse transcription polymerase chain reaction with RNAs from various rabbit tissues revealed that the VLDLR transcript with the O-linked sugar region (type-1 VLDLR) is the major transcript in heart and muscle, while the VLDLR transcript without the O-linked sugar region (type-2 VLDLR) predominates in non-muscle tissues, including cerebrum, cerebellum, kidney, spleen, adrenal gland, testis, ovary, and uterus. Hamster fibroblasts expressing type-2 VLDLR bound with relatively low affinity to beta-migrating very low density lipoprotein compared with type-1 VLDLR-transfected cells. In contrast, the internalization, dissociation, and degradation of the ligand were not significantly impaired in either type of VLDLR-transfected cell. The receptor proteins in type-2 VLDLR-transfected cells underwent rapid degradation and accumulated in the culture medium, while those in type-1 VLDLR-transfected cells were stable and resistant to proteolytic cleavage. Analysis of the O-linked sugars of both types of transfected cells suggested that the O-linked sugar region is the major site for O-glycosylation.

Structure-activity relationship and conformational analysis of monoglycosylceramides on the syngeneic mixed leukocyte reaction

We examined effects of alpha-, beta-galactosylceramides (CalCers) and alpha-, beta-glucosylceramides (GlcCers) on the syngeneic mixed leukocyte reaction (MLR) using spleen cells (responder cells) and dendritic cells (DC, stimulator cells). The DC pretreated with these alpha-monoglycosylceramides markedly stimulated the proliferation of spleen cells, in contrast to the little stimulatory effects produced by the DC pretreated with the corresponding beta-anomers. In addition, when we compared the effects of alpha-GalCer derivatives on the syngeneic MLR, it appeared that the 2"- and 3-hydroxyl groups in alpha-GalCers play a critical role in their stimulation of the MLR response. Based on these results, we performed a computer-aided molecular modeling study, and found that the orientations of the 2"-, 4"- and 3-hydroxyl groups common to alpha-GalCer and alpha-GlcCer are not accessible to those of inactive monoglycosyleeramides such as beta-GalCer. These results suggest that there might be a receptor-like site for alpha-monoglycosylceramides on the cells which are involved in the MLR response.

A novel acyl-CoA synthetase, ACS5, expressed in intestinal epithelial cells and proliferating preadipocytes

We report here the identification, characterization, and expression of a novel rat acyl-CoA synthetase (ACS) designated as ACS5. ACS5 consists of 683 amino acids and is approximately 60% identical to the previously characterized ACS1 and ACS2. ACS5 was overproduced in Escherichia coli cells and then purified to near homogeneity. The purified enzyme utilized a wide range of saturated fatty acids similar to those utilized by ACS1 and ACS2, but differed in its preference for C16-C18 unsaturated fatty acids. Northern blot analysis revealed that ACS5 mRNA is present most abundantly in the small intestine, and to a much lesser extent in the lung, liver, adrenal gland, adipose tissue, and kidney. In situ hybridization of rat ileum revealed abundant accumulation of ACS5 transcripts in foveolar epithelial cells. The hepatic level of ACS5 mRNA was significantly increased by refeeding a fat-free high sucrose diet and reduced by fasting or refeeding a high cholesterol diet, whereas that in the small intestine was not significantly altered by various dietary conditions. In contrast to the absence of ACS1 mRNA in undifferentiated 3T3-L1 preadipocytes, ACS5 mRNA was present in proliferating 3T3-L1 preadipocytes and its level remained unaltered during differentiation, suggesting that ACS5 may provide the acyl-CoA utilized for the synthesis of cellular lipids in proliferating preadipocytes.

Familial dysplasminogenemia with central retinal vein and cilioretinal artery occlusion

PURPOSE

To report a 49-year-old woman with unilateral central retinal vein occlusion and ipsilateral cilioretinal artery occlusion who showed familial dysplasminogenemia associated with elevated lipoprotein(a).

METHOD

Case report.

RESULTS

Extensive hemostatic and coagulation studies for causes of thrombosis, as well as family studies, disclosed decreased plasminogen activity without reduction of plasminogen antigen in the patient, her two siblings, and her two children. The patient also showed elevated lipoprotein(a).

CONCLUSION

The combination of decreased plasminogen activity and elevated lipoprotein(a) should be considered as a possible cause of retinal vein and artery occlusion.

[Antigen-induced airway hyperresponsiveness in infantile guinea pigs]

To investigate the development of airway hyperresponsiveness in infantile guinea pigs, animals (10 days old) were immunized twice and challenged by inhalation of 1% ovalbumin for 10 min with 7 days intervals. Similar to adult guinea pigs, infantile ones developed an increased airway responsiveness to acetylcholine 24 hr after antigen challenge. There was a marked increase in the number of total leukocytes, eosinophils and lymphocytes in bronchoalveolar lavage fluid (BALF). Suplatast tosilate (suplatast) and pemirolast potassium (pemirolast) given orally throughout the experiments suppressed the development of airway hyperresponsiveness in infantile animals. They showed similar potency in the suppression of eosinophil accumulation in BALF and lung tissue, while suplatast inhibited lymphocyte accumulation stronger than pemirolast. Collectively, the present model of airway hyperresponsiveness in infantile guinea pigs may be useful in predicting the efficacy of antiallergic agents in the treatment of asthmatic children.

Molecular cloning and characterization of Ca2+-dependent inducible nitric oxide synthase from guinea-pig lung

We have isolated a full-length cDNA for an inducible nitric oxide synthase (iNOS) from guinea-pig lung. The cDNA has a 3447 bp open reading frame encoding 1149 amino acid residues. The deduced amino acid sequence is approx. 80% identical with iNOS of human epithelial cells and murine macrophages. Consensus recognition sites for cofactors are highly conserved. COS cell lysate transfected with the guinea-pig iNOS shows significant levels of nitric oxide synthase (NOS) activity, and this is inhibited by 79% by chelation of Ca2+ ions. The NOS activity is restored in a concentration-dependent manner by increasing the free Ca2+ level. The NOS activity is also inhibited by trifluoperazine, a calmodulin antagonist, which suggests that the Ca2+ dependence is due to Ca2+-dependent calmodulin binding to the enzyme. Northern blot analysis reveals that the cloned iNOS mRNA is expressed in the lung and the colon in normal guinea pigs. Stimulation in vivo by lipopolysaccharide induces the expression of iNOS in the kidney, the spleen and the colon, but in the lung the same stimulation decreases its expression. These results suggest that the cloned guinea-pig iNOS is distinct in characteristics and expression from previously described iNOS forms.

Role of endogenous nitric oxide in allergen-induced airway responses in guinea-pigs

1. Endogenous nitric oxide (NO) can be detected in exhaled air and accumulates in inflamed airways. However its physiological role has not been fully elucidated. In this study, we investigated a role for endogenous NO in allergen-induced airway responses. Sensitised guinea-pigs were treated with NG-nitro-L-arginine methyl ester L-NAME (2.0 mM) or aminoguanidine (AG) (2.0 mM) 30 min before the allergen challenge, and 3 and 4 h after the challenge. Alternatively, L-arginine (2.4 mM) treatment was performed 30 min before, and 2 and 3 h after the challenge. In all groups, ovalbumin (OVA) challenge (2 mg ml(-1) for 2 min) was performed, and airway responses, NO production, infiltration of inflammatory cells, plasma exudation and histological details were examined. 2. Allergen-challenged animals showed an immediate airway response (IAR) and a late airway response (LAR), which synchronised with an increase in exhaled NO. Treatment with L-NAME and AG did not affect IAR while they significantly blocked LAR (72% and 80% inhibition compared to vehicle) and production of NO (35% and 40% inhibition). On the other hand, treatment with L-arginine did not affect IAR but potentiated LAR (74% augmentation). 3. In bronchoalveolar lavage (BAL) fluid, allergen-induced increases in eosinophils were reduced by 48% for L-NAME treatment compared to vehicle, and increased by 56% for L-arginine treatment. 4. Treatment with L-NAME significantly decreased airway microvascular permeability to both Monastral blue (MB) and Evans blue (EB) dye (50.6% and 44% inhibition). 5. We conclude that allergen-induced LAR is closely associated with NO production, and that NO plays a critical role in inflammatory cell infiltration and plasma exudation in the allergic condition.

Tandem lesions and other products in X-irradiated DNA oligomers

Free radicals interact with DNA bases to produce secondary radicals. The secondary radicals are reactive species and tend to interact with neighboring bases, resulting in DNA lesions with two adjacent modified bases. In this study the DNA oligomers d(CpApTpG) and d(CpGpTpA) were exposed to free radicals generated in anoxic aqueous solution by X irradiation. Four new lesions were identified in which adjacent guanine and pyrimidine bases are covalently bonded. One of the tandem lesions formed in d(CpGpTpA) has the C5 carbon atom of cytosine covalently bonded to the C8 carbon atom of guanine. Interestingly, the same bond is formed between the terminal bases in d(CpApTpG), resulting in a cyclized molecule.