Color Doppler imaging study of retrobulbar hemodynamics in chronic angle-closure glaucoma

PURPOSE

To evaluate the retrobulbar hemodynamics in patients with chronic angle-closure glaucoma (CACG) by using color Doppler imaging (CDI) and to correlate the degree of glaucomatous visual field loss with the hemodynamic parameters.

DESIGN

Prospective case series.

PARTICIPANTS AND CONTROLS

Twenty-six Chinese patients with CACG and 26 age-matched and gender-matched normal subjects were recruited. All CACG patients had history of chronic intraocular pressure (IOP) elevation and asymmetric visual field defects between their fellow eyes. After receiving laser peripheral iridotomy and/or filtration surgery, all of them had bilateral medication-free controlled IOP before enrolling into the study.

METHODS

Each subject underwent CDI measurement in the central retinal artery (CRA) and the nasal and temporal short posterior ciliary arteries (PCA). Visual fields of the CACG patients were obtained with Humphrey 24-2 program. The visual field defects were scored with the Advanced Glaucoma Intervention Study (AGIS) system. For each CACG patient, the eye with lower AGIS score was defined as the better eye and the eye with higher score as the worse eye.

MAIN OUTCOME MEASURES

Peak-systolic velocity (PSV), end-diastolic velocity (EDV) and resistance index (RI) were determined.

RESULTS

The EDV in the CRA and the temporal PCA was decreased significantly (P = 0.041 and 0.023, respectively) in the worse eyes of CACG patients compared with those in the control eyes. The better eyes of CACG patients showed no significant change in hemodynamic parameters compared with the control eyes. While comparing the fellow eyes of CACG patients, the worse eyes had significantly lower EDV in the temporal PCA (P = 0.012) than the contralateral better eyes. In 11 CACG patients with a difference of at least 8 in AGIS visual field scores between their fellow eyes, the worse eyes had significantly lower EDV (P = 0.041) in the CRA and lower PSV (P = 0.018) and EDV (P = 0.018) in the temporal PCA compared with those in the contralateral eyes. In multivariate regression analysis, the AGIS scores were significantly correlated with the PSV in the CRA (P = 0.015) and with the EDV (P < 0.001) and RI (P = 0.027) in the temporal PCA in patients with CACG.

CONCLUSIONS

Patients with well-controlled CACG may have decreased retrobulbar blood flow velocities and increased vascular resistance in the CRA and temporal PCA. The degree of retrobulbar hemodynamic impairment was well correlated with the degree of glaucomatous visual field loss.

Bilateral neurotrophic keratopathy complicating Vidian neurectomy

PURPOSE

To present a case of bilateral neurotrophic keratopathy with miosis after bilateral Vidian neurectomy for vasomotor rhinitis.

METHODS

Observational case report.

RESULTS

A 68 year-old man presented with irritation and blurred vision in both eyes 2 weeks after bilateral Vidian neurectomy. Slit-lamp examination revealed a large epithelial defect, typical of neurotrophic keratopathy, in the inferior two-thirds of cornea in both eyes. Corneal sensitivity test with a Cochet-Bonnet anesthesiometer and electrical study of the blink reflex indicated bilateral trigeminal dysfunction. Both pupils were miotic, and tests with hydroxyamphetamine 1% and epinephrine 0.1% showed postganglionic sympathetic nerve damage. The corneal epithelial defects healed after 2 months of treatment with systemic prednisolone, vitamin B(12) and tarsorrhaphy.

CONCLUSION

Neurotrophic keratopathy associated with dry eye syndrome may be a serious complication of Vidian neurectomy.

Local interstitial emphysema caused by meconium aspiration: report of one case

A neonate of meconium aspiration syndrome presented with respiratory distress and bilateral pneumothorax. The image studies, including chest X-ray, chest computed tomography and operation finding all showed cystic changes in the right lung. Therefore congenital cystic lesions of lung was the first impression. However, the pathologic report disclosed meconium aspiration with interstitial emphysema.

Visual acuity and contrast sensitivity in different types of posterior capsule opacification

PURPOSE

To compare the visual acuity (VA) and contrast sensitivity in 2 types of posterior capsule opacification (PCO) in pseudophakic eyes before and after neodymium:YAG (Nd:YAG) capsulotomy and to evaluate vision test results after Nd:YAG capsulotomy.

SETTING

Department of Ophthalmology, Taipei Veterans General Hospital, National Yang-Ming University, Taipei, Taiwan.

METHODS

Fourteen eyes with fibrosis-type PCO and 15 eyes with Elschnig-pearl-type PCO were enrolled prospectively. Before and 1 week after Nd:YAG capsulotomy, VA and contrast sensitivity were assessed using the illiterate E version of the Bailey-Lovie chart and the Vistech VCTS 6000 chart, respectively.

RESULTS

Before capsulotomy, the mean logMAR acuity in the group with Elschnig-pearl-type PCO was 0.47 +/- 0.32 (SD) and in the group with fibrosis-type PCO, 0.17 +/- 0.07. The difference between the 2 groups was significant (P =.002). After capsulotomy, there was no significant between-group difference (P >.05). Before capsulotomy, the contrast sensitivity was significantly worse (P <.01) at all spatial frequencies in the group with pearl-type PCO, especially at 6 cycles per degree. After capsulotomy, there was no significant between-group difference (P >.05) at any spatial frequency.

CONCLUSIONS

After cataract surgery, patients with pearl-type PCO had lower VA and contrast sensitivity than those with fibrosis-type PCO. An Nd:YAG capsulotomy improved the VA and contrast sensitivity in patients with both types of PCO.

Quantitative assessment of retinal thickness in diabetic patients with and without clinically significant macular edema using optical coherence tomography

PURPOSE

To assess patients with diabetic macular edema quantitatively using optical coherence tomography (OCT).

METHODS

OCT was performed in 14 eyes with diabetic retinopathy and ophthalmoscopic evidence of clinically significant macular edema (CSME) and in 19 diabetic eyes without CSME. Retinal thickness was computed from the tomograms at fovea and other 36 locations throughout the macula.

RESULTS

The mean +/- standard deviation foveal thickness was 255.6 +/- 138.9 microm in eyes with CSME, and 174.6 +/- 38.2 microm in eyes without CSME (p = 0.051). Within 2000 microm of the center of the macula, eyes with CSME had significantly thicker retina in the inferior quadrant than those without CSME (p < 0.01). The foveal thickness was correlated with logMAR visual acuity (gamma = 0.68, p < 0.01). OCT identified sponge-like retinal swelling and/or cystoid macular edema in 11 (58%) eyes without CSME, and in 12 (86%) eyes with CSME.

CONCLUSIONS

Criteria of CSME seem to be insufficient in really identifying macular edema. OCT may be more sensitive than a clinical examination in assessing diabetic macular edema and is a quantitative tool for documenting changes in macular thickening.

Cloning and characterization of zfBLP1, a Bcl-XL homologue from the zebrafish, Danio rerio

The importance of the Bcl-2 family proteins in normal vertebrate embryogenesis is being recognized; however, their regulatory mechanism is poorly understood. We report here the cloning and characterization of a novel zebrafish Bcl-2 family protein, zfBLP1. The zfBLP1 cDNA is 1942 nucleotides long, encoding a polypeptide of 238 amino acids. The primary sequence of zfBLP1 shares 50% identity to human Bcl-XL, and contains all four conserved BH domains of the Bcl-2 family proteins. Primary sequence analysis identified a consensus ER retention signal at the C-terminal end of zfBLP1. Northern blot analysis indicated that there were two major and two minor zfBLP1 mRNA species expressed during embryonic development. Among the two major mRNA species, the short one, approx. 3 kb in size, was expressed throughout embryonic development, while the long one, approx. 7 kb long, was not detectable until the gastrula stage. These results suggest that zfBLP1 is a novel Bcl-2 family protein under complicated regulations, and is likely to play an important role in zebrafish oogenesis and embryogenesis.

Is cadmium chloride-induced inter-sertoli tight junction permeability barrier disruption a suitable in vitro model to study the events of junction disassembly during spermatogenesis in the rat testis?

The events of germ cell movement during spermatogenesis are composed of intermittent phases of junction disassembly and reassembly. Although primary Sertoli cells cultured in vitro can be used to study junction reassembly, an in vitro model to study the events of junction disassembly is still lacking. We have assessed whether the CdCl(2)-induced inter-Sertoli tight junction (TJ) permeability barrier disruption in vitro can fill this gap. When Sertoli cells (1.2 x 10(6) cells/cm(2)) were cultured on Matrigel-coated bicameral units to allow the assembly of inter-Sertoli TJs, it was manifested by a steady rise in transepithelial electrical resistance across the Sertoli cell epithelia. Exposure of these cells on day 1 (i.e. 24 h after their isolation) to CdCl(2) at 5-10 microM for 8 h could perturb the inter-Sertoli TJ assembly dose dependently without any apparent cytotoxicity. Likewise, when cells were exposed to CdCl(2) (0.1-5 microM) on day 4 for 8 h after inter-Sertoli TJs were already assembled, CdCl(2) also perturbed the maintenance of inter-Sertoli TJ permeability barrier dose dependently without signs of cell cytotoxicity. Although the perturbed inter-Sertoli TJs were not capable of resealing even after the removal of CdCl(2), the presence of testosterone (T) at 1 x 10(-9) M allowed resealing of the inter-Sertoli TJ barrier after CdCl(2) was removed, whereas the presence of 2 x 10(-7) M testosterone even protected Sertoli cells from CdCl(2)-induced damage. More important, the reassembly of inter-Sertoli TJs after CdCl(2)-induced TJ disruption was accompanied by changes in cellular gene expression of occludin and urokinase plasminogen activator, which mimicked their patterns during inter- Sertoli TJ assembly in vitro without CdCl(2) treatment. Based on these results, it is apparent that CdCl(2)-induced inter-Sertoli TJ disassembly is a potential in vitro model to study the events of junction disassembly.

Reversible inhibition of spermatogenesis in rats using a new male contraceptive, 1-(2,4-dichlorobenzyl)-indazole-3-carbohydrazide

The oral male contraceptive agent 1-(2,4-dichlorobenzyl)-indazole-3-carbohydrazide (AF2364) is a new analogue of indazole-carboxylic acid. AF2364 was orally administered to rats at 50 mg/kg body weight once weekly for five consecutive weeks. The effects on fertility efficacy, hormonal profile, organ weights, tissue morphology, and serum microchemistry were examined. Complete infertility was noted in rats 29 days after the initial dose of AF2364 and continued until 90 days. Fertility resumed in 25% of the group after 104 days and had resumed in 75% of the rats by the last mating at 197 days. Morphological examination of the testis showed rapid exfoliation of elongated spermatids and the generation of large multinucleated cells 6 days after the first treatment, with depletion of most germ cells after 40 days. Normal spermatogenesis was noted in 95% of the tubules in the animals that were fertile at 210 days. Morphological analysis of the epididymal compartments revealed reduced lumen size, whereas the prostate exhibited an increase in the glandular lumen with a reduction in epithelium height. No morphological changes were detected in the kidney, liver, and cerebrum by light microscopy. Kidney and liver function, as evaluated by serum chemistry, were not affected by the drug treatment. AF2364 did not alter the levels of FSH, and only minimal changes were noted for LH and testosterone, suggesting that the hypothalamic-pituitary-testicular axis was not affected. These results illustrate the potential of AF2364 as a male contraceptive.

Transforming growth factor-beta3 perturbs the inter-Sertoli tight junction permeability barrier in vitro possibly mediated via its effects on occludin, zonula occludens-1, and claudin-11

Throughout spermatogenesis, inter-Sertoli tight junctions (TJs) that create the blood-testis barrier in the rat must be disassembled and reassembled to permit the timely passage of preleptotene spermatocytes from the basal to the adluminal compartment of the seminiferous epithelium. However, the mechanism(s) and the participating molecules that regulate this event are largely unknown. Although there is no in vitro model to study the event and regulation of inter-Sertoli TJ disassembly, primary cultures of Sertoli cells in vitro can be used to study junction assembly. In this study, we sought to investigate whether cytokines are involved in the inter-Sertoli TJ assembly in vitro. Sertoli cells isolated from 20-day-old rats were cultured at a density of 0.5-1.2 x 10(6) cells/cm(2) on Matrigel-coated dishes or bicameral units for 8-9 days. The steady-state messenger RNA levels of basic fibroblast growth factor (bFGF), transforming growth factor (TGF)-beta2, and TGF-beta3 at different time points were assessed by semiquantitative RT-PCR. In selected experiments, the assembly of inter-Sertoli TJs was monitored by transepithelial electrical resistance measurement. It was found that there was no change in the expression of basic fibroblast growth factor throughout the entire culture period. However, there was a 2-fold reduction in the expression of TGF-beta2 and TGF-beta3 at the time inter-Sertoli TJs were being assembled. On days 5-8, after the inter-Sertoli TJs had been assembled, the Sertoli cell steady-state messenger RNA levels of TGF-beta2 and TGF-beta3 increased by as much as 3- and 6-fold, respectively, when compared with Sertoli cells on days 1-3 when TJs were being assembled. Also, it was found that recombinant TGF-beta3 added to Sertoli cells cultured in vitro at 1.2 x 10(6) cells/cm(2) on Matrigel-coated bicameral units perturbed the inter-Sertoli TJ permeability barrier dose-dependently. Moreover, the presence of TGF-beta3 also inhibited the transient and/or basal expression of several TJ-associated proteins, which include occludin, zonula occludens-1, and claudin-11 when inter-Sertoli TJs were being assembled in vitro. These results suggest that TGF-beta plays a crucial role in regulating the complicated biochemical events of junction assembly in the testis.

Regulation of Sertoli cell myotubularin (rMTM) expression by germ cells in vitro

Recent studies have shown that rat myotubularin (rMTM), the homolog of human myotubularin, which is a putative protein tyrosine phosphatase (PTP), is expressed by Sertoli cells in the rat testis. In addition, a significant increase in its steady-state mRNA level was detected in Sertoli cells at the time of inter-Sertoli tight junction (TJ) assembly in vitro. Since the interplay of protein kinases and phosphatases that determines the intracellular phosphoprotein content can, in turn, regulate the assembly and maintenance of TJ and anchoring junctions (AJ) in vitro, as demonstrated in different cell types, such as Madin-Darby canine kidney (MDCK) cells, endothelial cells, and Sertoli cells, rMTM may be an important molecule in regulating the assembly and maintenance of inter-Sertoli TJs during spermatogenesis. We thus sought to characterize its regulation. During testicular maturation, it was shown that the rMTM steady-state mRNA level increased drastically with aging. The expression of rMTM increased by as much as 2-4-fold in the rat testis at 45-60 days of age versus 20 days of age, coinciding with the onset of spermiation. This result seemingly suggests that rMTM may participate in the release of spermatids by disassembling the Sertoli-spermatid AJs, since PTP inhibitor was shown to perturb the inter-Sertoli TJ permeability barrier in vitro. Unexpectedly, when Sertoli cells were isolated from 20-, 45-, and 90-day-old rats and the steady-state rMTM level was quantified, it was shown that there is a drastic reduction in rMTM expression in adult Sertoli cells. Studies that used Sertoli-germ cell cocultures and Sertoli cells incubated with increasing germ cell-derived proteins have shown that the high level of testicular rMTM expression in the testis might be maintained by germ cells. Although work remains to be done to delineate the role of rMTM in the testis, these results illustrate that germ cells play a very active role in regulation testicular function by altering the phosphoprotein content.

Treatment of giant cell tumor of the distal radius

The results of surgical treatment of giant cell tumors of the distal radius were reviewed in 12 patients between 1982 and 1995. All 12 patients had Grade III lesions. Six of the 12 patients were treated using intralesional curettage with local excision, and the other six patients underwent en bloc resection with total condyle (four of the six by osteoarticular allograft, and the other two by fibular autograft) reconstruction with the aim of preserving the functional joint. There were no early or late complications such as infection, graft fracture, implant failure, or nonunion. No local tumor recurrence was seen in either group during the average followup of 6 years (range, 3-16 years). The best functional result was seen in the patients treated with intralesional curettage. The functional result of the resection group was good, achieving an average of 69% (range, 56%-83%) of their range of motion and 70% (range, 63%-77%) of their grip strength on the contralateral side. Intralesional excision should not be excluded as a possible treatment of Grade III lesions, although en bloc resection was used more commonly for these lesions because of tumor surgery reasons. Grade III lesions were treated with curettage when the tumor did not invade the wrist, destroy more than 50% of the cortex, or break through the cortex with an extraosseous mass in more than one plane. Reconstruction with osteoarticular allograft after en bloc resection is recommended in this non-weightbearing joint when there is contraindication for curettage of the lesion.

[Comparison of the effects of two different breastcare methods]

The purpose of this study was to compare the effects of two breastcare methods-one with moist heating pad (the pad group) and the other with moist hot towel (the towel group). Data were collected from May, 1996 to April, 1997 in a southern hospital in Taiwan. Mothers who breastfed, had no postpartum complications and had a healthy newborn were recruited in the study. Mothers who breastfed less than 2 days and those newborns without a complete body weight record were excluded. The numbers of participants were 94 in the towel group and 52 in the pad group. The tools used in this study were the questionnaire developed by the researchers, the heating pad, and the newborn body weight scale. The results revealed that: (1) there is no differences in the changes of newborns' body weight between the two groups; (2) the mothers in the pad group felt more comfortable, convenient and private than those in the towel group; (3) nurses spent less time helping mothers in the pad group than those in the towel group. The conclusion was that the heating pad could substitute for the hot towel in the breastcare method.

N-Acyl-1,2,3,4a,5,10b-hexahydro-[1]benzopyrano-[3,4-b][1,4]oxazine-9-carbonitriles as bladder-selective potassium channel openers

Optically active N-acyl-5,5-dimethyl-1,2,3,4a,5,10b-hexahydro-[1]benzopyrano[3,4-b][1,4]oxazine-9-carbonitriles 2-22 were synthesized as rigid analogues of cromakalim. The (4aR, 10bR)-N-benzoyl derivative (-)-11 was identified as a bladder-selective KCO (IC50, bladder = 8.2 microM, C50, portal vein = 34.5 microM). Among the analogues of 11 with substitution on the benzoyl moiety, the 3-methyl analogue (-)-14 showed highly potent and selective activity at portal vein (IC50, bladder = 279 microM, IC50, portal vein = 0.54 microM). The 4-bromo analogue (-)-19 (IC50, bladder = 2.0 microM, IC50, portal vein = 8.1 microM) and the 4-hydroxy analogue (-)-21 (IC50, bladder = 3.8 microM, IC50, portal vein = 75 microM) showed enhanced activity at the bladder, while maintaining unprecedented bladder selectivity in vitro. The N-benzenesulfonyl analogue (-)-22, a bioisoster of (-)-11, showed similar activity at the bladder with enhanced selectivity (IC50, bladder = 11.6 microM, IC50, portal vein = 120 microM).

Cloning and characterization of a novel nuclear Bcl-2 family protein, zfMcl-1a, in zebrafish embryo

The importance of the Bcl-2 family proteins in normal vertebrate embryogenesis is being recognized; however, their regulatory mechanism is poorly understood. To elucidate the embryonic roles of Bcl-2 family proteins, we cloned and characterized the first zebrafish Bcl-2 family protein, zfMcl-1a. Zebrafish Mcl-1a shows the highest homology to rat Mcl-1 and contains several conserved BH domains of the Bcl-2 family proteins. It also contains a nuclear localization signal (NLS). Using EGFP reporter analysis, we verified the nuclear localization of zfMcl-1a. Deletion of the NLS resulted in distribution of the fusion protein in the cytoplasm. Northern blot analysis indicated that zfMcl-1a mRNA is 1.5 kb and was expressed in oocytes and throughout embryonic development. Notably, the expression of zfMcl-1a transcript was significantly downregulated during gastrulation. These results suggest that zfMcl-1a is a novel nuclear Bcl-2 family protein and is likely to play an important role in zebrafish oogenesis and embryogenesis.

Regulatory influence of germ cells on sertoli cell function in the pre-pubertal rat after acute irradiation of the testis

While germ cell regulation of Sertoli cells has been extensively explored in adult rats in vivo, in contrast, very little is known about germ cell influence on Sertoli cell function at the time when spermatogenesis begins and develops. In the present study various Sertoli cell parameters (number, testicular androgen binding protein (ABP) and testin, serum inhibin-B and, indirectly, follicle-stimulating hormone (FSH)) were investigated after the exposure of 19-day-old rats to a low dose of 3 Grays of gamma-rays. Differentiated spermatogonia were the primary testicular targets of the gamma-rays, which resulted in progressive maturation depletion, sequentially and reversibly affecting all germ cell classes. Testicular weight declined to a nadir when pachytene spermatocytes and spermatids were depleted from the seminiferous epithelium and complete or near complete recovery of spermatogenesis and testicular weight was observed at the end of the experiment. Blood levels of FSH and ABP were normal during the first 11 days after irradiation, when spermatogonia and early spermatocytes were depleted. While the number of Sertoli cells was not significantly affected by the irradiation, from days 11-66 after gamma-irradiation, ABP production declined and FSH levels increased when pachytene spermatocytes and spermatids were depleted and the recovery of these parameters was only observed when spermatogenesis was fully restored. Comparison of the pattern of change in serum levels of inhibin-B and testicular levels of testin and of germ cell numbers strongly suggest a relationship between the disappearance of spermatocytes and spermatids from the seminiferous epithelium and the decrease in levels of inhibin-B and increase in levels of testin from 7 to 36 days post-irradiation. Levels of testin and inhibin-B were restored before spermatogenesis had totally returned to normal. In conclusion, this in vivo study shows that pre-pubertal Sertoli cell function is under the complex control of various germ cell classes. This control presents clear differences when compared with that previously observed in adult animals and depends on the Sertoli cell parameter of interest, as well as on the germ cell type.

Statistics in ophthalmic research: two eyes, one eye or the mean?

BACKGROUND

Ophthalmic data, while different among individuals, are usually similar between fellow eyes of the same individual. This study was designed to illustrate alternative approaches to account for the correlation between fellow eyes. This is important for making inferences using data from both eyes.

METHODS

With the use of a real data set from a population-based study, we described the distribution of intraocular pressure (IOP) by estimating the mean and standard deviation (SD) and evaluated the potential risk factors of higher IOP based on the regression method. The units of observation studied were of both eyes, right eye only, left eye only, the eyes with higher IOP and the mean value of both eyes. Furthermore, the generalized estimating equation (GEE) method was used to account for the correlation between fellow eyes in the regression analysis. Results and inferences from the different approaches were compared.

RESULTS

The analysis included all the eyes, providing the largest sample size and unbiased estimates of the mean and SDs. There were some discrepancies among different approaches in the regression analysis. The GEE method simultaneously evaluated the effects of both eyes, and increased precision and enhanced inferences.

CONCLUSIONS

Inconsistent results among different ophthalmic studies result from variations in not only study design and courses but also statistical methods. Making the best use of appropriate statistical techniques, which account for between eye correlation, provides valid statistical inferences.

Rat testicular myotubularin, a protein tyrosine phosphatase expressed by Sertoli and germ cells, is a potential marker for studying cell-cell interactions in the rat testis

The full-length cDNA encoding the entire open reading frame (ORF) of rat myotubularin (rMTM) was isolated from a rat testis expression library by PCR. Among the three approximately 2.9-kb cDNAs that were sequenced, one clone was different from the other two clones. It contained seven extra amino acids of FVVLNLQ; this short stretch of extra sequence was found between Gln(421) and Phe(422) within the SET (Suvar3-9, Enhancer-of-zeste, Trithorax) interacting domain (SID) of rMTM. The rMTM ORF had 1,713 bp encoding for a 571 amino acid polypeptide and a calculated molecular weight of 65.8 kDa. A comparison between its deduced amino acid sequence and the GenBank database using BLAST revealed a 53.1% identity with human myotubularin protein (hMTM1), which is a member of the protein tyrosine phosphatase (PTP) family associated with X-linked myotubular myopathy. A 22 amino acid peptide NH(2)-TKVNERYELCDTYPALLAVPAN was synthesized based on the deduced amino acid sequence of rMTM and used for antibody production. By using immunoblot analysis, a 66-kDa protein was indeed detected in both Sertoli and germ-cell cytosols. rMTM mRNA was found in various tissues but was predominantly expressed in the testis, ovary, and skeletal muscle. Sertoli cell rMTM expression was stimulated by germ cells and enhanced when inter-Sertoli junctions were being assembled in vitro. A drastic reduction in testicular rMTM steady-state mRNA level correlated with the depletion of germ cells from the testis in vivo following either glycerol or lonidamine treatment. These results indicate that rMTM is a rat homologue of hMTM1 that may be a useful marker in monitoring the events of cell-cell interactions in the testis.

An Aspergillus chitosanase with potential for large-scale preparation of chitosan oligosaccharides

A chitosan-degrading fungus, designated Aspergillus sp. Y2K, was isolated from soil. The micro-organism was used for producing chitosanase (EC 3.2.1.132) in a minimal medium containing chitosan as the sole carbon source. The induced chitosanase was purified to homogeneity from the culture filtrate by concentration and cationic SP-Sepharose chromatography. The purified enzyme is a monomer with an estimated molecular mass of 25 kDa by SDS/PAGE and of 22 kDa by gel-filtration chromatography. pI, optimum pH and optimum temperature values were 8.4, 6.5 and 65-70 degrees C, respectively. The chitosanase is stable in the pH range from 4 to 7.5 at 55 degrees C. Higher deacetylated chitosan is a better substrate. Chitin, xylan, 6-O-sulphated chitosan and O-carboxymethyl chitin were indigestible by the purified enzyme. By endo-splitting activity, the chitosanase hydrolysed chitosan to form chitosan oligomers with chitotriose, chitotetraose and chitopentaose as the major products. The enzyme hydrolyses chitohexaose to form chitotriose, while the chitopentaose and shorter oligomers remain intact. The N-terminal amino acid sequence of the enzyme was determined as YNLPNNLKQIYDDHK, which provides useful information for further gene cloning of this enzyme. A 275 g-scale hydrolysis of chitosan was performed. The product distribution was virtually identical to that of the small-scale reaction. Owing to the simple purification process and high stability of the enzyme, it is potentially valuable for industrial applications.

Testin induction: the role of cyclic 3',5'-adenosine monophosphate/protein kinase A signaling in the regulation of basal and lonidamine-induced testin expression by rat sertoli cells

Results of previous in vitro and in vivo studies have illustrated that the expression of testin by Sertoli cells is tightly associated with the disruption of Sertoli-germ cell junctions. In the present study, treatment of rats with cadmium chloride (CdCl(2)), which disrupted the inter-Sertoli tight junctions, failed to induce any changes in testicular testin expression. In contrast, lonidamine, an antispermatogenic drug that rearranges the Sertoli cell membrane microfilament structure causing a disruption of Sertoli-germ cell adhesion junctions, induced a drastic increase in testicular testin expression when administered orally. Lonidamine-induced Sertoli cell testin expression involved both ongoing RNA and de novo protein synthesis. Basal testin expression remained stable during the 27-h incubation with actinomycin D but required de novo protein synthesis in vitro. An inhibitor of protein kinase A, Rp-cAMPS, caused a 50% inhibition of Sertoli cell testin expression at 10 microM within 24 h. A biphasic response was noted in testin expression when forskolin was included in the Sertoli cell culture, and high concentrations of cAMP analogues (1 mM) rapidly reduced testin expression. However, lonidamine can abolish the inhibitory effect of cAMP analogues on Sertoli cell testin expression. These results illustrate that the induction of testin expression may involve several signal transduction pathways.

Lonidamine and analogue AF2785 block the cyclic adenosine 3', 5'-monophosphate-activated chloride current and chloride secretion in the rat epididymis

The cystic fibrosis transmembrane conductance regulator (CFTR) or the small conductance cAMP-activated chloride channel encoded by the CFTR gene has been shown to play an important role in the formation of the epididymal fluid microenvironment. Mutation of the gene has led to widespread effects on male reproduction. Like other ion channels, CFTR is amenable to pharmacological intervention. Blocking CFTR in the epididymis could in principle lead to disruption of the epididymal fluid environment. We report for the first time two indazole compounds: lonidamine and 1-(2, 4-dichlorobenzyl)-indazole-3-acrylic acid (AF2785) are potent blockers of CFTR in the epididymis. When added to the external solution under whole-cell patch clamp conditions, AF2785 and lonidamine inhibited the cAMP-activated chloride current in rat epididymal cells with apparent IC(50) values of 170.6 and 631.5 microM, respectively; by comparison the IC(50) value for diphenylamine-2-carboxylate, a well-known chloride channel blocker was 1294 microM. In cultured rat epididymal epithelia mounted in a Ussing chamber, AF2785 and lonidamine inhibited the cAMP-stimulated short-circuit current (a measure of chloride secretion) when added to the apical bathing solution with potency greater than any known chloride channel studied. It is proposed that in view of the important role CFTR plays in male reproduction, further study with these and other new indazole compounds for their CFTR blocking actions can provide a new avenue of research into the development of novel male contraceptives.

In vitro regulation of extracellular superoxide dismutase in sertoli cells

Rat Sertoli and germ cells express extracellular superoxide dismutase (SOD(EX)), however, the relative level of SOD(EX) expressed by these cells was not known. We report herein germ cells consisting largely of spermatogonia, spermatocytes, and round spermatids expressed only one-third SOD(EX) as that of Sertoli cells when examined by semi-quantitative RT-PCR. While cocultures of germ cells with Sertoli cells failed to induce any changes in SOD(EX) expression possibly due to the limited number of cells that can be supported by the in vitro culture system dissimilar to the in vivo condition, incubation of total germ cell-conditioned medium with Sertoli cells was able to significantly inhibit Sertoli cell SOD(EX) expression dose-dependently suggesting a germ cell-derived soluble factor(s) may regulate SOD(EX) in the testis. On the other hand, cytokines such as TGF-beta1, beta-NGF, or FGF and steroid hormones such as estradiol-17beta, progesterone, testosterone, and DHT were unable to effect the expression of Sertoli cell SOD(EX). However, FSH at 100 ng/dish was able to induce a significant increase in Sertoli cell SOD(EX) expression. While cytokines, the known mediators of the inflammatory response, were unable to affect Sertoli cell SOD(EX) expression, the induction of generalized inflammation in vivo was able to cause a 2- to 2.5-fold increase in testicular SOD(EX) expression concomitant with a transient increase in the liver but not in the brain. Taken collectively, these results demonstrate that while SOD(EX) is an important antioxidant enzyme protecting the testis from reactive oxygen species, the mechanism(s) regulating its expression may involve an array of molecules and is a complicated cellular event.

Population-based study on prevalence and risk factors of age-related cataracts in Peitou, Taiwan

BACKGROUND

Age-related cataracts are the main cause of blindness throughout the world. Nonetheless, population-based data on the epidemiology of age-related cataracts among Taiwanese populations are not readily available. This study was conducted to estimate the prevalence of age-related cataracts and to determine the relationships of age, gender, blood pressure, diabetes and smoking to the risks of age-related cataracts in an urban Taiwanese population.

METHODS

The study was part of a population-based survey of eye diseases among residents aged 50 years or older in Peitou Precinct, Taipei, Taiwan. Of the 2,700 eligible persons, 2,038 (75.5%) underwent a standard evaluation protocol including dilated slit-lamp examination, a questionnaire of medical and ophthalmic histories and blood pressure measurement.

RESULTS

Among the participants, 1,040 were diagnosed with age-related cataracts. The prevalence was 51.0% (95% confidence interval, 48.9%-53.2%). Nuclear opacity was the most prevalent type (718/1,040; 35.2%) of cataracts, followed by posterior subcapsular opacity (311/1,040; 15.3%) and cortical opacity (163/1,040; 7.8%). An increased risk of age-related cataracts was associated with female gender (p = 0.002). When a single type of lens opacity was considered, diabetes was significantly associated with a posterior subcapsular cataract (p = 0.022). Overall, older women with diabetes and relatively lower diastolic blood pressure were more likely to have age-related cataracts.

CONCLUSIONS

The study provided the first prevalence data on age-related cataracts in an urban Taiwanese population and highlighted the relationships of age, gender, blood pressure and diabetes to the frequency and type of age-related cataracts. The results can assist in the design and implementation of intervention programs to reduce the prevalence of age-related cataracts.

The antihypertensive and cardioprotective effects of (-)-MJ-451, an ATP-sensitive K(+) channel opener

ATP-sensitive K(+) (K(ATP)) channel openers have been shown to be a potential class of therapeutic agents for the control of cardiovascular diseases, including angina, arrhythmias, and hypertension. In this study, the pharmacological activity of 6-cyano-3S,4R-dihydro-2, 2-dimethyl-2H-3-hydroxy-4-[5S-(1-hydroxymethyl)-2-oxo-1-pyrrolidinyl] -1-benzopyran ((-)-MJ-451), a synthetic K(ATP) opener, was evaluated in anesthetized rat models and in isolated rat thoracic rings. Results demonstrated that intravascular injection of (-)-MJ-451 (0. 02, 0.05 and 0.1 mg/kg) produced an immediate, dose-related reduction in mean arterial blood pressure in anesthetized spontaneously hypertensive rats (SHR), which persisted for more than 3 h and was not accompanied by reflex tachycardia. The hemodynamic changes were completely abolished by pretreatment with glibenclamide (4 mg/kg, i.v. bolus), a selective K(ATP) channel blocker. In isolated thoracic aorta, (-)-MJ-451 (10 nM-3 microM) produced a concentration-dependent vasodilator effect on the phenylephrine (0.3 microM)-induced vasoconstriction. Moreover, (-)-MJ-451 relaxed the thoracic aorta contracted by low (5, 20 and 30 mM), but not high (40 and 60 mM) concentrations of extracellular potassium. In addition, (-)-MJ-451 showed cardioprotective effects in the rat model of 45-min left coronary artery occlusion followed by 1-h reperfusion. In myocardial ischemia, pretreatment with (-)-MJ-451 (2, 5 and 10 microg/kg, i.v. bolus) significantly reduced the incidence of ventricular fibrillation and the mortality, also reducing the total number of ventricular premature contractions, total duration of ventricular tachycardia and ventricular fibrillation. A significant reduction in infarct size was noted in three (-)-MJ-451 (2, 5 and 10 microg/kg)-treated groups. Also, the cardioprotective effects of (-)-MJ-451 were virtually abolished by pretreating the rats with glibenclamide (4 mg/kg, i.v. bolus). In conclusion, (-)-MJ-451, through opening the K(ATP) channel, exerted antihypertensive and cardioprotective effects. Therefore, it is suggested that (-)-MJ-451 has potential in the treatment of hypertension or acute myocardial infarction.

Effects of lonidamine on testicular and epididymal proteins in the rat

The mechanism responsible for the antispermatogenic activity of lonidamine (LND) [1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxylic acid], a drug with low systemic toxicity and lack of significant hormonal effects, is still unclear but may be related to alterations of Sertoli cell proteins. Here, we confirmed that a single oral dose of LND (100 mg/kg b.w.) to sexually mature Sprague-Dawley rats causes shrinkage and weight reduction of the testes after 48 h. These macroscopic changes correlated with histologic alterations revealed by light microscopy, consistent with partially reversible inhibition of spermatogenesis. When the testes and the epididymides of animals treated with or without LND were homogenized and analyzed by the Bradford assay, a significant increase of total protein content was observed after 24 and 48 h. When these homogenates were analyzed by concanavalin blotting, specific changes of the major rat macroglobulins, i.e. alpha(1)-inhibitor-3, alpha(2)-macroglobulin, and alpha(1)-macroglobulin, were noted. In particular, LND caused a decrease of testicular alpha(1)-inhibitor-3, but not an increase of testicular alpha(2)-macroglobulin, indicating a mild local inflammatory response to the drug.

Changes in the expression of junctional and nonjunctional complex component genes when inter-sertoli tight junctions are formed in vitro

Throughout spermatogenesis, germ cells move progressively from the basal to the adluminal compartment, which is accompanied by continual disassembly and reassembly of intercellular junctions suggesting germ cell movement is composed of intermittent phases of junction disassembly and reassembly. A study was performed to correlate the expression of junctional-complex components (such as zonula occludens-1 [ZO-1], a tight-junction component protein) and nonjunctional complex components (such as urokinase-type plasminogen activator [uPA], a serine protease; cathepsin L, a cysteine protease; alpha2-macroglobulin, a nonspecific protease inhibitor; and cystatin C, a cysteine protease inhibitor) at the time when inter-Sertoli tight junctions were established in vitro. This is an attempt to investigate whether the expression of nonjunctional component genes also correlates with the formation of inter-Sertoli tight junctions in vitro. This is part of an effort to understand the physiologic elements of germ cell movement in the epithelium. Sertoli cells cultured in vitro are known to undergo programmed cell death. To ensure that the changes in target gene expression were not the result of apoptosis, Sertoli cells were cultured in vitro at densities of 0.25, 0.75, and 3 x 10(6) cells/cm2 for up to 7 days on bicameral culture units coated with Matrigel (Collaborative Research) and were assessed by morphologic analysis and agarose gel electrophoresis. It was noted that many of the Sertoli cells cultured at 3 x 10(6) cells/cm2 underwent apoptosis by day 7, in contrast to cultures at 0.25 and 0.75 x 10(6) cells/cm2 illustrating the Sertoli cell number per unit of area may be an important parameter to be considered when studying Sertoli cell function in vitro. Also, it was shown that the expression of ZO-1 increased significantly between days 2 and 3 prior to the establishment of inter-Sertoli tight junctions assessed by transepithelial resistance measurement (TER), which illustrates that ZO-1 can be used as a marker to monitor this cellular event. More interestingly, there was also a transient increase in the expression of uPA and cathepsin L between days 2 and 3 at the time preceding the formation of tight junctions. In Sertoli cells cultured at low density (2 x 10(4) cells/cm2), when a confluent monolayer of cells could not form, there were no changes in the expression of either ZO-1, uPA, or cathepsin L throughout the 7-day culture period. These results show that the establishment of specialized junctions, such as tight junctions between Sertoli cells in vitro, may require the participation of both junctional and nonjunctional complex components.