Optical coherence tomography in measuring retinal nerve fiber layer thickness in normal subjects and patients with open-angle glaucoma

OBJECTIVES

To investigate image characteristics and thickness of the retinal nerve fiber layer (RNFL) in normal and glaucomatous eyes using optical coherence tomography (OCT), and analyze the relationship between RNFL thickness and visual field index.

METHODS

Eighty-three normal persons (150 eyes) and 83 patients with primary open angle glaucoma (POAG, 149 eyes) underwent OCT examinations with 3.4 mm diameter circle scan to calculate the RNFL thickness. Statistical analysis was used to compare differences in RNFL thickness in quadrants and means between the normal and glaucomatous groups and the different stages of POAG. Linear correlation and regression analysis were used to show the correlation between RNFL thickness and visual field index of 115 eyes in glaucomatous patients. Reproducibility, sensitivity and specificity of RNFL measurements using OCT were evaluated.

RESULTS

RNFL thickness measured by OCT in normal subjects was thicker in superior and inferior, less in temporal, and thinnest in nasal quadrants. The curve showed double peaks. RNFL of glaucomatous patients showed local thinning or defect, diffuse thinning, or both. The mean RNFL thicknesses of the normal group in the temporal, superior, nasal and infelor quadrants were 90.1 +/- 10.8 microns, 140.4 +/- 10.5 microns, 85.2 +/- 14.0 microns, and 140.4 +/- 9.7 microns, respectively with a mean of 114.2 +/- 6.0 microns. The numbers for the glaucomatous group were respectively 56.0 +/- 31.0 microns, 81.0 +/- 36.3 microns, 47.1 +/- 27.5 microns, and 73.4 +/- 38.4 microns for the four quadrants, with a mean of 64.6 +/- 28.8 microns. There was a significant difference in RNFL thickness between the normal and glaucomatous groups (P < 0.000), and the three stages (early, developing and late) of glaucomatous groups (P < 0.000). There was a close negative relationship between RNFL thickness and visual field index (r = -0.796, P < 0.0001). The sensitivity and specificity of RNFL thickness in POAG measured using OCT were 93.3% and 92.0%, respectively.

CONCLUSIONS

OCT can quantitatively measure RNFL thickness differences between normal persons and glaucomatous patients. RNFL thickness gradually decreases while visual field defect increases with the development of POAG.

High-frequency (140-GHz) time domain EPR and ENDOR spectroscopy: the tyrosyl radical-diiron cofactor in ribonucleotide reductase from yeast

High-frequency pulsed EPR and ENDOR have been employed to characterize the tyrosyl radical (Y*)-diiron cofactor in the Y2-containing R2 subunit of ribonucleotide reductase (RNR) from yeast. The present work represents the first use of 140-GHz time domain EPR and ENDOR to examine this system and demonstrates the capabilities of the method to elucidate the electronic structure and the chemical environment of protein radicals. Low-temperature spin-echo-detected EPR spectra of yeast Y* reveal an EPR line shape typical of a tyrosyl radical; however, when compared with the EPR spectra of Y* from E. coli RNR, a substantial upfield shift of the g(1)-value is observed. The origin of the shift in g(1) was investigated by 140-GHz (1)H and (2)H pulsed ENDOR experiments of the Y2-containing subunit in protonated and D(2)O-exchanged buffer. (2)H ENDOR spectra and simulations provide unambiguous evidence for one strongly coupled (2)H arising from a bond between the radical and an exchangeable proton of an adjacent residue or a water molecule. Orientation-selective 140-GHz ENDOR spectra indicate the direction of the hydrogen bond with respect to the molecular symmetry axes and the bond length (1.81 A). Finally, we have performed saturation recovery experiments and observed enhanced spin lattice relaxation rates of the Y* above 10 K. At temperatures higher than 20 K, the relaxation rates are isotropic across the EPR line, a phenomenon that we attribute to isotropic exchange interaction between Y* and the first excited paramagnetic state of the diiron cluster adjacent to it. From the activation energy of the rates, we determine the exchange interaction between the two irons of the cluster, J(exc) = -85 cm(-)(1). The relaxation mechanism and the presence of the hydrogen bond are discussed in terms of the differences in the structure of the Y*-diiron cofactor in yeast Y2 and other class I R2s.

[Expression of delta 6-fatty acid desaturase gene from Mortierella alpina in Saccharomyces cerevisiae]

delta 6-fatty acid desaturase is the rate-limiting enzyme of the desaturation of linoleic acid in the production of an essential fatty acid, gamma-linolenic acid. The 1.4 kb fragment in plasmid pTMACL6 encoding delta 6-fatty acid desaturase from Mortieralla alpina ATCC16266 was subcloned into the yeast-E. coli shuttle vector pYES2.0, thus an expression recombinant plasmid pYMAD6 containing target gene was constructed and obtained in the SC-Ura media. The pYMAD6 was introduced into defective mutant INCSc1 of Saccharomyces cerevisiae by LiAc method. When linoleic acid was provided as an exogenous substrate to the yeast cultures expressing delta 6-fatty acid desaturase activity under appropriate media and temperature condition, the level of gamma-linolenic acid reached 31.6% of the total yeast fatty acids by GC-MS detecting, which is the highest report of delta 6-fatty-acid desaturase gene in S. cerevisiae.

Phacoemulsification in patients with secondary glaucoma caused by uveitis

PURPOSES

To evaluate the effect of phacoemulsification in the patients with uveitis, secondary glaucoma and complicated cataract.

METHODS

Phacoemulsification and implantation of a foldable intraoucular len was performed in 12 patients(13 eyes) with uveitis, secondary glaucoma and complicated cataract. The complications, intraocular pressures (IOP), and visual acuity were observed postoperatively.

RESULTS

No severe complication was found in the patients postoperatively or within the operation procedure. The visual acuity was improved after the operation (P < 0.05). The intraocular pressures and/or the number of antiglaucoma medications reduced in 3 months of the follow-up time.

CONCLUSION

Phacoemulsification is the best way to treat the patients with secondary glaucoma and complicated cataract caused by uveitis.

The evolution of ribonucleotide reduction revisited

Ribonucleotide reductases (RNRs) catalyze the conversion of both purine and pyrimidine nucleotides to deoxynucleotides in all organisms and provide all the monomeric precursors essential for both DNA replication and repair. RNRs have been divided into three classes on the basis of their unique metallo-cofactors. The exquisitely controlled free radical chemistry used by all RNRs, and the commonality of the structures of the subunits where the nucleotide reduction process occurs, together provide compelling evidence for the importance of chemistry in the divergent evolution of RNRs from a common progenitor.

[The cultivation, freezing-state preservation and resuscitation of human iris pigment epithelial cells in vitro]

PURPOSE

To establish the culture of human iris pigment epithelial cells in vitro and study the freezing-state preservation and resusciation.

METHODS

The iris pigment epithelial specimens from human eyes were cultured in vitro. Based on the cell-frozen principle, the cultured cells were collected, then frozen in liquid nitrogen and resuscitation.

RESULTS

Cultured iris pigment epithelial cells were obtained. Under the inverted light microscope, primary cells appeared multigonal and arranged in monolayer, there were abundant pigment granules in the cytoplasm and the nuclei each of which contained 1 or 2 nuceoli wre relatively transparent. Under the transmission electron microscope, there were plenty of microvilli at the cell membrane and desmosomes present in the intercellular space. 6 groups of cells were frozen. The resuscitation exeriment was carried out for 4 times, every times being successful. All of the resuscitated rates were more than 90%.

CONCLUSION

The human iris pigment epithelial cells were cultured in vitro successfully, they can also be frozen and resuscitated, which will be useful in studies of pathogenesis for some eye disease.

[A quantitative study of poincare dispersed-dot plot for heart rate variability]

Poincare dispersed-dot plot is an important nonlinear dynamics method that can effectively describe the attractor shape. Yet studies in the past generally processed the plot in a graphic mode without further discussion on the quantitative indices. That was not suited for clinical application and studies. So, based on the shape of Poincare dispersed-dot plot, we propose a group of quantitative parameters of Poincare dispersed-dot plot: plot square(SQ), long axis (LA), short axis(SA), and angle related to long-axis and short-axis(ALS). According to the characters of the heart rate Poincare dispersed-dot plot, we have posed the 'tortoise crawling and counting' algorithm to get these four quantitative parameters. We have tested these four quantitative parameters with clinical and animal experiment data. The results demonstrate that these four parameters are of certain specificity to heart diseases, indicating that these parameters might be useful for clinical diagnosis.

[To screen, clone and sequence TIGR gene mutation in Chinese patients with primary open- angle glaucoma]

OBJECTIVE

To study trabecular meshwork induced glucocorticoid response protein (TIGR) gene mutation in Chinese patients with primary open-angle glaucoma (POAG).

METHODS

(1) From 70 patients with POAG and 20 normal controls, TIGR gene which consists of three exons (7 pairs of primer) was amplified by polymerase chain reaction (PCR). The mutation of PCR amplification products was evaluated by single-stranded conformation polymorphism (SSCP). (2) After the above PCR products were cloned into the PT-Adv vectors, the construction plasmids were evaluated by Ecor I endonuclease and direct sequence was performed.

RESULTS

(1) With SSCP screening, the single strand band abnormality was found in the middle fragments of the third exon (the sixth pair of primer) of TIGR gene in two patients with POAG, but the control group appeared normal. (2) The two samples using clone and sequence showed that one had a 'GAT'- to- 'AAT' transition at amino acid Asp 338 Asn mutation; the base sequence of another one had no change. These results suggested that mutation rate of TIGR gene in Chinese patients with POAG be only 1.4% (1/70), being lower than that of foreigners.

CONCLUSION

The pathogenesis of Chinese patients with POAG may be related with TIGR gene mutation, but the mutation rate is lower than that in foreigners, indicating that the mechanism of POAG in China and aboard is different and the pathogenesis of POAG has difference in regions and races.

Size of emptied plaque cavity following spontaneous rupture is related to coronary dimensions, not to the degree of lumen narrowing. A study with intravascular ultrasound in vivo

OBJECTIVE

To identify any potential relations between the size of an emptied plaque cavity and the remodelling pattern, plaque or vessel dimensions, lumen narrowing, and other ultrasonic lesion characteristics.

DESIGN

Intravascular ultrasound was used to examine prospectively 51 ruptured ulcerated coronary plaques. Cross sectional area measurements comprised lumen, vessel, plaque, and emptied plaque cavity. Lumen narrowing was calculated as 1 - (lesion lumen area/reference lumen area) x 100%. A remodelling index was calculated as lesion vessel area/reference vessel area, and plaques were divided into those with values > 1.05 (group A) and </= 1.05 (group B).

RESULTS

Of the total of 51 plaques, 36 (71%) were assigned to group A and 15 (29%) to group B. In neither group was there a significant difference in reference dimensions and lumen narrowing. However, lesion vessel (mean (SD): 22.6 (8.1) mm(2) v 17. 5 (4.3) mm(2); p = 0.006) and plaque areas (15.8 (6.2) mm(2) v 12.8 (3.2) mm(2); p = 0.03) were greater in group A than in group B. The cavity inside the plaque was larger in group A than in group B (2.8 (1.6) mm(2) v 1.8 (0.9) mm(2); p = 0.007) and showed a positive linear relation with lesion and reference vessel size (r = 0.58 and 0.56, respectively; p < 0.001), but not with lumen narrowing.

CONCLUSIONS

The size of the emptied cavity inside ruptured plaques is on average larger in lesions with adaptive vascular remodelling, and shows a linear relation with lesion plaque and vessel size and with the reference dimensions, but not with the degree of lumen narrowing.

[Phacoemulsification with silicone foldable intraocular lens implantation through a small incision in glaucomatous eyes after filtering surgery]

OBJECTIVE

To investigate the method of cataract extraction in eyes that had undergone glaucoma filtering surgery and its effects on filtering bleb.

METHODS

Phacoemulsification with posterior chamber intraocular lens implantation was performed on 262 eyes with a preexisting filtration bleb, in which at the temporal clear cornea a lateral or inferior lateral limbal incision was selected, the pupil sphincter was cut and the iris was sewed for the small and fixed pupil.

RESULTS

The postoperative visual acuity of all patients improved in different degrees, with >or= 0.5 in 74.0% in the first month. The postoperative IOP increased by 3.08 mmHg. The functional filtering bleb was not apparently cicatrized.

CONCLUSIONS

Glaucomatous eyes with cataract after filtering operation can rehabilitate their visual acuity and maintain the functional filtering bleb by phacoemulsification with foldable intraocular lens implantation through a temporal clear corneal incision or lateral scleral pocket incision. Theoretically, the effect of a transparent corneal incision on filtering bleb is less than that of a scleral pocket incision.

Long-term effect of Nd:YAG laser posterior capsulotomy on intraocular pressure

OBJECTIVE

To study the long-term effect of Nd:YAG capsulotomy on intraocular pressure (IOP).

METHODS

We reviewed the records of patients with bilateral pseudophakia who received Nd:YAG capsulotomy in only 1 eye. Using the Wilcoxon rank sum test, we compared the mean change in IOP in eyes before and after capsulotomy with that of the noncapsulotomy eyes at corresponding time intervals. Using multiple regression tests, we analyzed the factors significantly associated with postcapsulotomy long-term IOP increases.

RESULTS

The study included 100 patients who were followed up for a median of 1.5 years after capsulotomy. The mean +/- SD age of the study group was 76+/-7 years, and 37 patients had glaucoma. The changes in IOP in the eyes treated with capsulotomy were significantly higher than those in noncapsulotomy eyes at each time interval following capsulotomy. The long-term IOP increase was significantly associated with the IOP increase measured 1 hour after the capsulotomy (P =. 001). Patients with glaucoma were more likely to require long-term additional glaucoma medication than were nonglaucoma patients to require initial glaucoma therapy after the capsulotomy (P =.002).

CONCLUSION

After Nd:YAG capsulotomy, long-term IOP is often elevated above precapsulotomy baselines, especially in glaucoma patients or patients who experience a significant IOP increase within hours after the capsulotomy.

Safety of intracoronary Doppler flow measurement

BACKGROUND

With the introduction of Doppler-tipped guide wires, intracoronary Doppler flow measurement has been increasingly accepted as an additional diagnostic approach in the catheterization laboratory. However, the safety of intracoronary Doppler flow measurement has not been well-investigated. The purpose of our study was to evaluate the safety of intracoronary Doppler flow measurement using the Doppler FloWire (Cardiometrics, Mountain View, Calif).

METHODS AND RESULTS

A total of 906 patients were examined by intracoronary Doppler with a 0.014-inch or an 0.018-inch Doppler FloWire. For coronary flow reserve measurement, intracoronary injection of adenosine or papaverine was used. Of the patients studied, 77 were cardiac transplant recipients and 829 were patients who had not received a transplant, of whom 617 had undergone diagnostic coronary procedures and 212 had coronary interventions. In 27 (2.98%) of 906 patients adverse cardiac events were observed. Fifteen (1.66%) of 906 patients had severe transient bradycardia develop (asystole or second- to third-degree atrioventricular block) after intracoronary administration of adenosine, 14 of which occurred in the right coronary artery and 1 in the left anterior descending artery. Nine (0.99%) of 906 patients had coronary spasm during the passage of the Doppler wire (5 in the right coronary artery, 4 in the left anterior descending artery). Two (0.22%) of 906 patients had ventricular fibrillation during the procedure. Hypotension with bradycardia and ventricular extrasystole each occurred in 1 (0.11%) of 906 patients. The incidence of complication was significantly higher in transplant recipients than in patients who underwent either diagnostic or interventional procedures (12.99% vs 2.43% vs 0.94%, P <.001). The Doppler measurements in the right coronary artery were associated with a higher incidence of complications, especially bradycardia, compared with the left anterior descending and the left circumflex arteries (right coronary, 5.87% vs left anterior descending, 1.05% vs left circumflex, 0.17%; P <.001). All complications were cured medically.

CONCLUSION

Intracoronary Doppler flow measurement with Doppler wires and intracoronary administration of adenosine is a safe method. However, severe complications such as bradycardia and coronary spasm can occur. Attention should be paid to the examination of the right coronary artery, especially in heart transplant recipients.

[Optical coherence tomography applied for measurement of nerve fiber layer thickness in normal eyes]

OBJECTIVE

To evaluate the efficiency of optical coherence tomography (OCT) on quantifying retinal nerve fiber layer (RNFL) thickness and its reproducibility and investigate the difference of RNFL thickness between different groups.

METHODS

According to their age, 152 eyes of 152 normal subjects were classified into six groups (such as 10 year, 20 year group, etc.), and investigated by OCT to measure the RNFL thickness. Each subject had circular scans around the optic nerve with a circle size of 3.46 mm. The RNFL thickness in different groups was analyzed. Intraclass correlation coefficient (ICC) in fifty eyes of 37 subjects was calculated.

RESULTS

The mean RNFL thickness of 152 eyes was (90.09 +/- 10.81) microm, (140.27 +/- 10.60) microm, (85.03 +/- 14.01) microm, (140.27 +/- 9.70) microm and (114.11 +/- 6.08) microm (temporal, superior, nasal, inferior and the mean of the whole layer, respectively). Least significant difference (LSD)-t test was applied for multiple thickness comparisons of the mean and different quadrants among different groups. The results showed there were significant differences between the 60 year group and others except the 50 year group in temporal, superior, inferior quadrants and mean RNFL thickness (P = 0.000 - 0.019), and between each of 10 to 40 year groups and each of 50 to 60 year groups in the mean RFNL thickness (P = 0.000 - 0.026). ICCs of RNFL thickness measured by OCT were 0.78, 0.66, 0.64, 0.52 and 0.74 (temporal, superior, nasal, inferior and mean, respectively).

CONCLUSIONS

Normal RNFL thickness can be measured accurately by OCT. There are some differences of RNFL thickness between different groups in normal persons.

[Automated analysis technology of electrocardiograms]

Study of detection and analysis methods for electrocardiograms(ECGs) has been developed for more a decade. But it is still existing some problems because of patient idiosyncrasy. The automated analysis of ECGs was simply summarized at the present for existing problems and with possible way to solve those troubles. We have reviewed preprocessing methods of waveform detection of ECGs and diagnosis techniques of arrhythmia.

The preliminary study of interferon-gamma gene transfection to human Tenon's capsule fibroblasts in vitro

PURPOSE

To investigate the results of the interferon-gamma (IFN-gamma) gene transfer and transient expression in human Tenon's capsule fibroblast in vitro in order to find a way to gene therapy in vivo.

METHOD

Using LipofectAMINE, IFN-gamma gene was transferred in human Tenon's capsule fibroblasts with plasmid pcDNA3 IFN-gamma. Its mRNA transcription and protein expression were determined by RT-PCR and flow cytometry assay respectively.

RESULT

The human Tenon's capsule fibroblasts transferred the IFN-gamma gene can express the IFN-gamma in transcription and protein level transiently.

CONCLUSION

IFN-gamma gene can be transferred successfully and expressed expressed efficiently in human tenon's capsule fibroblast in vitro.

[The clinical analysis of 260 combined surgery of glaucoma and cataract]

PURPOSE

To evaluate the efficacy of the combined surgery of glaucoma and cataract.

METHODS

We reviewed 260 consecutive cases (279 eyes) who underwent the combined procedure of glaucoma and cataract. The patients were divided into three groups: group 1: extracapsular cataract extraction combined with trabeculectomy; group 2: extracapsular cataract extraction and intraocular lens implantation combined with trabeculectomy; group 3: cataract phacoemulsification and intraocular lens implantation combined with trabeculectomy; We analyzed and compared the postoperative visual acuity (VA), intraocular pressure(IOP) and complications among three groups.

RESULTS

16.2%, 32.4% and 43.5% of patients in three groups achieved 0.3 or better VA. The VA improved rate were 46.6%, 70.4% and 78.3% respectively. The mean postoperative IOP of three groups were 12.72 +/- 6.66 mmHg(1 mmHg = 0.133 kPa), 13.01 +/- 5.26 mmHg, 12.63 +/- 4.66 mmHg(compared with preoperative IOP, P < 0.01). The complications of group 3 were much less than those of the other two groups.

CONCLUSION

The combined surgery can control the IOP effectively; The triple procedure can improve the VA rapidly and the phacoemulsification technique can decrease the complications.

[Advancement in the study of embryonic stem cells and the emerging potential promising future of ocular tissue engineering]

The advancement of the study in embryonic stem cells and tissue engineering makes it promising to effectively solve the intractable problems in the present ophthalmic practice. The problems include: no effective measures to regain the visual function of the patients with late stage glaucoma or retinal diseases, shortage of appropriate biocompatible donor tissues in treating ocular surface diseases.

Corrected coronary flow velocity reserve: a new concept for assessing coronary perfusion

OBJECTIVES

In order to limit the variability of coronary flow velocity reserve (CFVR), we analyzed which factors independently affect CFVR and established a new parameter integrating these factors.

BACKGROUND

Coronary flow velocity reserve (CFVR) is a frequently used parameter for evaluating the physiological significance of epicardial stenosis and microvascular function. Since CFVR measurements are done in substantially different hemodynamic and clinical situations, interpretation of CFVR requires correction for major influencing factors.

METHODS

In 141 patients with angina-like symptoms and angiographically unobstructed coronary arteries, intracoronary Doppler measurements were performed in at least two coronary vessels. Coronary flow velocity reserve was calculated as the ratio of hyperemic average peak velocity (hAPV), after intracoronary bolus of adenosine, to baseline average peak velocity (bAPV).

RESULTS

Analysis of covariance revealed that only bAPV (p < 0.0001) and age (p < 0.0001) were independent factors influencing CFVR. Based on a regression model for estimation of predicted CFVR values, individual CFVR values (CFVRind) obtained at different bAPV and age were transformed in corrected CFVR values (CFVRcorr) by relating them to a mean bAPV of 15 cm/s and a mean age of 55 years. The transformation from CFVRind into CFVRcorr for the left anterior descending artery can be done by using the following equation: CFVRcorr = 2.85*CFVR(ind)*10(0.48*log(bAPV)+(0.0025*age)-1.16). When applying this new parameter to conditions assumed to cause microvascular dysfunction, analysis showed that only patients with diabetes showed a significant decrease of traditional CFVR and CFVRcorr, whereas a history of hypertension and current smoking habit had no influence on CFVRcorr.

CONCLUSIONS

The concept of CFVRcorr standardizes CFVR for bAPV and age as the major physiological determinants. Especially in patients with microvascular dysfunction, this approach may help to discriminate between conditions directly affecting vasodilator reserve and conditions primarily affecting bAPV.

Reporter LacZ gene transfer into cultured ocular cells of human eyes in vitro

OBJECTIVE

To investigate whether a reporter LacZ gene could be transferred into cultured ocular cells of human eyes in vitro.

METHODS

Fibroblast cells of Tenon's capsule, trabecular meshwork cells, and muscle cells in the ciliary body of human eyes were cultured and the pcDNA3-LacZ gene was transferred into these cells using a cationic liposome delivery system. The cells were subsequently fixed with 4% paraformaldehyde, mixed with X-gal, then observed under a microscope.

RESULTS

Blue stain was seen in the cytoplasm of the cultured cells under the microscope, demonstrating the successful transfer of the LacZ gene into these cells.

CONCLUSION

Reporter LacZ gene was easily transferred into the cultured ocular cells in vitro. This provides insights into the transfer of the genes into these cells to study the pathogenesis and therapy of glaucoma.

[Partial laryngectomy for T3 glottic carcinoma]

OBJECTIVE

To explore the possibility of partial laryngectomy for T3 glottic carcinoma and selection of reconstruction methods.

METHODS

From January 1986 to January 1994, 78 patients with T3 glottic carcinomas were treated by partial laryngectomy. The operative techniques and the reconstruction methods were retrospectively analyzed.

RESULTS

The overall 3 and 5 years survival rates were 88.5% and 75.6% respectively. The local recurrence rate was 15.4%. The reconstruction methods for laryngeal defect repariring following partial laryngectomy were the use of pyriform sinus mucosa with thyroid perichondrium, epiglottic cartilage and bi-pedicaled and bi-muscular flap of strap muscle. The function of respiration, phonation and deglutition recovered well.

CONCLUSION

The partial laryngectomy is suitable for T3 glottic carcinoma. The selection of reconstruction method is based on the size of laryngeal defect.

Gene mutation in patients with primary open-angle glaucoma in a pedigree in China

OBJECTIVE

To investigate the genetic basis of the pathogenesis of a Guangzhou (GZ.1) pedigree with primary open-angle glaucoma (POAG).

METHODS

DNA fragments of the trabecular meshwork inducible glucocorticoid response protein (TIGR) gene from 4 typical POAG patients and 2 normal subjects were amplified by polymerase chain reaction (PCR). The amplified PCR fragment was cloned into a pT-Adv vector, and direct sequencing was carried out on an ABI-373 automated DNA sequencer using dyeterminator chemistry to detect the mutation.

RESULTS

The TIGR gene mutation was identified in the selected subjects of this pedigree. This mutation is a "C-to-T" transition at position 370, different from that of western countries and equivalent to the position change found in Japanese patients with familial POAG. No mutation was found in the TIGR gene fragment in 2 normal subjects of the pedigree.

CONCLUSIONS

These preliminary results provide insights into the pathogenesis of POAG by the TIGR gene mutation, and into the underlying action of the different mutations in oriental and western peoples.

Preliminary study on in vitro induced differentiation of embryonic stem cells into neurons

PURPOSE

To study preliminarily in vitro induced differentiation of embryonic stem cells into neurons for further investigation of an alternative for the treatment of glaumatous neuropathy.

MATERIALS AND METHODS

Supernatant of cultured Buffalo rat liver cells (buffalorat liver cell-conditioned medium, BRL-CM) was used for culturing embryonic stem cells (ES-D3 cell line). Morphological features of undifferentiated ES cells were studied by HE staining and electron microscopy. Based on the methods used by Bain et al, we modified the methods and used retinoic acid (RA) as an inducer to differentiate ES-D3 cells and cytosine arabinoside (Ara-C) as inhibitor of proliferative cells. The growth of the cells was observed under phase contrast microscope.

RESULTS

ES-D3 cells cultured by BRL-CM grew in aggregates and remained undifferentiated. Electromicroscopy showed large nucleus and a large amount of mitochondria in undifferentiated ES cells and many processes on the surfaces. In the first day after the adding of retinoic acid, some neuron-like cells with one, two or more processes were present. In the second day after adding RA and the first day after the plus of 10 microns Ara-C, a large amount of neuron-like cells appeared, with the formation of neuron-like networks.

CONCLUSIONS

Combined use of RA and Ara-C can induce ES cells to differentiate into neuron-like cells. Our present preliminary study might provide insights into an alternative for the treatment of glaucomatous neuropathy by the transplantation of embryonic stem cells.

The analysis of pedigree GZ (Guangzhou). 1 with primary open angle glaucoma

PURPOSE

To analyze the hereditary modality of primary open-angle glaucoma in China.

METHODS

The genetic form of Pedigree GZ. 1 was analyzed using Mandalian hereditary rules.

RESULTS

Pedigree GZ. 1 had following characteristics: 1) The pedigree had four generations, and there existed POAG patients in each generation; 2) Each patient had a parent with POAG. If the parents didn't suffer from the disease, their children would not. 3) The incidence of POAG in the relatives of the patients was 1/2. In addition, The age of onset, intraocular pressure, fundus and prognosis was different from each other in the patients.

CONCLUSIONS

1) Pedigree GZ. 1 is inherited as an autosomal dominant trait. 2) There exists individual differences of clinical manifestations in POAG patients.

[A clinical comparative study of interferon alpha-2b with mitomycin C applied in glaucoma filtering operation]

OBJECTIVE

To compare the results of interferon alpha-2b (IFN alpha-2b) with mitomycin C (MMC) treatment in trabeculectomy.

METHOD

41 cases 68 eyes with late stage of primary open angle glaucoma (POAG) were randomly studied by treatment with IFN alpha-2b or MMC following trabeculectomy, each group consisting of 34 eyes. Of the cases, 27 were bilateral, one eye was designed to use IFN alpha-2b, and the other eye, apply MMC. All patients were ranged from 15 to 40 years old, and they all received the surgery the first time. The surgical procedure was similar in all eyes. The IFN alpha-2b treated eyes were subconjunctivally injected 5 x 10(5) IU at filtering bleb when the operation was finished immediately and on the postoperative day 3, 7, 10 and 14, respectively. The MMC-receiving eyes were intraoperatively administered with 0.25 mg/ml via a sponge under the conjunctival flap for 5 minutes. The follow-up was ranged from 6 to 15 months.

RESULTS

(1) The 12th month life-table success rate of functional bleb formation was (70.95 +/- 9.72)% in IFN alpha-2b-treated group and (77.01 +/- 10.51)% in MMC-received group, the difference being not statistically significant (u = 0.2165, P > 0.05). The eyes with IFN alpha-2b tended to form type II blebs were according to Kronfeld classification, whereas type I blebs were commonly seen in MMC-treated eyes (chi(2) = 6.261, P < 0.05). The percentages of intraocular pressure between 10 - 15 mmHg on postoperative month 3, 6, 9 and 12, respectively in IFN alpha-2b group were higher than that in MMC group. (2) The 12th month life-table complete and qualified success rates were (70.95 +/- 9.72)% and (94.59 +/- 5.26)% in IFN alpha-2b group, (65.15 +/- 10.51)% and (84.61 +/- 7.26)% in MMC group, respectively (u = 0.8174, 0.1011, P > 0.05). (3) Complications induced by IFN alpha-2b were rare, mainly involving transient corneal epithelial defect, whereas by MMC included thin-wall blebs, persistent hypotony and hypotonous maculopathy. The decrease of visual acuity was seen in 44.1% of the cases in MMC group, whereas only 17.6% occurred in IFN alpha-2b group (chi(2) = 5.217 4, P < 0.05).

CONCLUSION

IFN alpha-2b has similar effect as MMC to reduce the risk of failure of glaucoma filtration surgery, but it has more advantages over because of its fewer complications.

New management of angle-closure glaucoma by phacoemulsification with foldable posterior chamber intraocular lens implantation

OBJECTIVE

To investigate the management of angle-closure glaucoma by phacoemulsification with foldable posterior chamber intraocular lens (PC-IOL) implantation.

DESIGN

Retrospective, noncontrolled interventional case series.

PARTICIPANTS

In 36 eyes with angle-closure glaucoma (ACG), there were 18 eyes with primary acute angle-closure glaucoma (PACG), 14 eyes with primary chronic angle-closure glaucoma (PCCG), 3 eyes with secondary acute angle-closure glaucoma (SACG) and 1 eye with secondary chronic angle-closure glaucoma (SCCG).

INTERVENTION

Phacoemulsification with posterior chamber intraocular lens implantation.

MAIN OUTCOME MEASURES

Postoperative visual acuity, IOP, axial anterior chamber depth.

RESULTS

After a mean postoperative follow-up time of 8.81 +/- 7.45 months, intraocular pressure was reduced from a preoperative mean of 23.81 +/- 17.84 mmHg to a postoperative mean of 12.54 +/- 4.73 mmHg (P = 0.001). Mean anterior chamber depth was 1.75 +/- 0.48 mm preoperatively and 2.29 +/- 0.38 mm postoperatively (P = 0.000). Best spectacle-corrected visual acuity in 36 eyes ranged from 0.01 to 0.7 (20/200 to 20/30) postoperatively, which was better than preoperative VA ranging from hand movement to 0.4 (20/50) (P = 0.000).

CONCLUSION

Phacoemulsification with posterior chamber foldable intraocular lens implantation can be a good alternative in treating angle-closure glaucoma.

Bifunctional effect of human IFN-gamma on cultured human fibroblasts from Tenon's capsule

PURPOSE

To study the effect of human IFN-gamma on in vitro cultured human fibroblasts from Tenon's capsule.

MATERIALS AND METHODS

The effect of different concentrations of human IFN-gamma and mitomycin-C (MMC), 5-fluorouracil (5-Fu) on cultured human Tenon's capsule fibroblasts (HTCF) was measured using a MTT [3-(4, 5-dimethylthiazo-2-yl)]-2, 5-diphenyltetrazolium bromide; Thiazolyl blue) colorimetric assay. The results were analyzed using ANOVA of the statistical package for social sciences (SPSS) 9.0 version. The difference was considered to be significant if P < 0.05.

RESULTS

The effects of MMC and 5-Fu on the growth of HTCF were negative, while the effects of IFN-gamma on the growth of HTCF were both negative (10(2)-10(4) units/ml in two experiments) and positive (10(6), 10(5), 10 units/ml in two experiments). The inhibition rate of MMC ranged from 5.73% to 46.9%, which was similar to the inhibition rate of 5-Fu ranged from 12.49% to 38.92% (P = 0.351). The inhibition rate of IFN-gamma in two experiments was smaller than MMC and 5-Fu (P < 0.05).

CONCLUSION

IFN-gamma has bifunctional effect (both enhancement and inhibition) on proliferation of cultured HTCF. The antiproliferative effect of IFN-gamma was weaker than MMC and 5-Fu. Further study has to be carried out to document the inhibition of scar formation of filtration bleb by IFN-gamma and the molecular mechanisms of its bifunctional effect on HTCF proliferation.

Fabrication and Characterization of a New Self-Assembled Monolayer of Fullerene Dicarboxylic Acid Derivative and Its Photoelectric Conversion Property

A new fullerene self-assembled monolayer (SAM) which has the property of photoelectric conversion is reported here. The SAM was fabricated on hydrophilic substrates by an esterification reaction. The SAM is characterized by contact angle, AFM, UV spectrum, and cyclic voltammetry. A cathodic photocurrent of 226 nA/cm(2) was obtained. Copyright 2000 Academic Press.

The nitroreductase/CB1954 combination in Epstein-Barr virus-positive B-cell lines: induction of bystander killing in vitro and in vivo

Epstein-Barr virus (EBV)-based gene delivery vectors that preferentially express toxic genes in EBV-infected cells could be used to target EBV-positive tumors for destruction. We have shown previously that the cytosine deaminase (CD) enzyme, which converts the prodrug 5-fluorocytosine (5-FC) into the toxic compound 5-fluorouracil efficiently kills EBV-positive cells in the presence of 5-FC, with a substantial bystander killing effect in vitro and in vivo. To identify the optimal enzyme/prodrug combination for treating EBV-positive lymphomas, we have compared the effectiveness of the CD/5-FC combination with the nitroreductase (NTR)/CB1954 combination for killing EBV-positive B-cell lines. NTR metabolizes CB1954 into an alkylating agent that cross-links DNA. When the CD gene or the NTR gene were transfected into two different EBV-positive B-cell lines in vitro, approximately 90% of cells were killed in a prodrug-dependent manner, although the transfection efficiency was <5%. However, severe combined immunodeficient mouse tumors containing either 30% or 100% of NTR-expressing Burkitt lymphoma (Jijoye) cells were growth inhibited, but not cured, by treatment with intraperitoneal CB1954 (20 mg/kg/day) for 10 days. These results suggest that the NTR/CB1954 combination induces efficient bystander killing of EBV-positive B-cell lines in vitro but may not be as effective as the CD/5-FC combination for treating B-cell lymphomas in vivo.

[A preliminary report of a new technique: non-penetrating trabecular surgery]

OBJECTIVE

To evaluate the clinical effect of nonpenetrating trabecular surgery with sodium hyaluronate gel implant in Primary Open-Angle Glaucoma(POAG).

METHODS

Twenty-four eyes of 22 patients with medically uncontrolled POAG were underwent nonpenetrating trabecular surgery with hyaluronate gel implant. The procedure was performed involing excising a deep-sclera tissue that flush with innerwall of Schlemm' s canal without opening the anterior chamber, then placing a 3 mm x 4.5 mm x 0.5 mm or 3.5 mm x 3.5 mm x 3.5 mm sodium hyaluronate gel implant under the scleral flap respectively. The postoperative Intraocular Pressure (IOP), Inflammation and fitering bleb were analysised. All of patients were undertaken ultrasound biomicroscopy (UBM) to evaluate the surgery site on postoperative 1-3 months. Mean follow-up was 3.9 +/- 2.2 months.

RESULTS

The IOP decreased from a mean preoperative value of 24.4 +/- 9.1 mmHg to a mean postoperative value of 15.1 +/- 3.7 mmHg (P < 0.01). The number of anti-glaucomatous medications by topically or systemically was reduced from preoperative sorts of 2.8 +/- 1.4 to postoperative sorts of 0.7 +/- 1.0 (P < 0.01). The visual acuity remained stable, 6 eyes had IOP elevated and 2 eyes had occured hyphema. The complications such as flat chamber, inflammation and detachment of choroid were not observed. The UBM showed that the hyaluronate gel implant wasn't degraded and a transparent liquid space was formed under the scleral flap in all of patients on postoperatively 1-3 month. The filtering blebs were formed in some patients.

CONCLUSION

Nonpenetrating trabecular surgery with hyaluronate gel implant can effectively lower IOP and reduce the number of anti-glaucomatous medications. No severe complications occured. With a simple postoperative nursing, it can be performed in clinic. It is proved to be a promising and new special technique to treat glaucoma.

New signs characteristic of myocardial bridging demonstrated by intracoronary ultrasound and Doppler

BACKGROUND

Large discrepancies exist concerning the incidence of myocardial bridging. This has been reported to be 0.5%-2.5% following coronary angiography but 15%-85% following autopsy. The purpose of the study was to use intravascular ultrasound and intracoronary Doppler to study the morphology and flow characteristics of myocardial bridging in order to find feasible parameters of this syndrome.

METHODS AND RESULTS

Intravascular ultrasound was performed in 62/69 patients in whom typical angiographic 'milking effects' were present. In 48 patients, intracoronary Doppler was performed. A specific, echolucent 'half moon' phenomenon surrounding the myocardial bridge was found in all the patients. The thickness of the half moon area was 0.47 +/- 0.19 mm in diastole and 0.52 +/- 0.23 mm in systole. There was systolic compression of the myocardial bridge with a lumen reduction during systole of 36.4 +/- 8.8%. Using intracoronary Doppler, a characteristic early diastolic 'finger tip' phenomenon was observed in 42 (87%) of the patients. All patients showed no or reduced antegrade systolic flow. Coronary flow velocity reserve was 2.03 +/- 0. 54. After intracoronary nitroglycerin injection, retrograde systolic flow occurred in 37 (77%) of the 48 patients, with a velocity of -22. 2 +/- 13.2 cm. s(-1). Intravascular ultrasound revealed atherosclerotic involvement of the proximal segment in 61 (88%) of the 69 patients, with an area stenosis of 42 +/- 13%. No plaques were found in the bridge or distal segments in the 62 patients in whom it was possible to introduce the ultrasound catheter throughout the bridging segment.

CONCLUSION

Myocardial bridging is characterized by the following morphological and functional signs: a specific, echolucent half moon phenomenon over the bridge segment, which exists throughout the cardiac cycle; systolic compression of the bridge segment of the coronary artery; accelerated flow velocity at early diastole (finger-tip phenomenon); no or reduced systolic antegrade flow; decreased diastolic/systolic velocity ratio; retrograde flow in the proximal segment, which is provoked and enhanced by nitroglycerin injection.

[Preliminary experimental study on commitment differentiation of embryonic stem cells induced by corneal limbal stroma in vitro]

PURPOSE

To investigate the possibility of commitment differentiation of embryonic stem cells (ES cells) induced by corneal limbal stroma.

METHODS

Superficial corneal limbal stroma and lentis epithelium from New Zealand white rabbit were used for feeder layer for ES-D3 cells culture to induce the ES cells differentiation into corneal limbal stem cells. The differentiated ES cells were determined by light microscope and electronic microscope.

RESULTS

1. The proliferation of differentiating ES cells which cultured on corneal surface stroma layer around the corneal limbus was slow. The appearance of induced ES cells were uniform cells with much larger size than undifferentiated ES cells, and the nucleoli become long and thin under electronic microscope, but the size of ES cells cultured on deep stroma maintain as small as undifferentiated ES cells. The ES cells cultivated on surface stroma layer around the corneal limbus appeared microvilli 2 weeks after grafting into subcutaneous of athymic mice. 2. Lentis epithelium can only delay but not induce the ES cells differentiation to corned limbal stem celluloid.

CONCLUSION

These results suggest that the superficial corneal limbal stroma has a potential ability to induce ES cells commitment differentiation. The tertiary embryo induction may not occur in vitro.

[Recent development of endoscope system in ophthalmology]

The new ophthalmic laser microendoscope are widely used in a variety of clinical settings up-to-date. In this paper, we will describe the technical characteristics, recent development and prospectie evaluation of the microendoscope system.

Prevalence of microvascular disease in patients with significant coronary artery disease

Coronary flow velocity reserve (CFVR) measurement using intracoronary Doppler techniques has been increasing accepted for the assessment of physiological significance of epicardial stenosis and the functional changes after coronary interventions. However, large discrepancy exists concerning the acute changes of CFVR immediately after intervention. The purpose of this study was to investigate the prevalence of microvascular dysfunction in patients with significant coronary artery disease. Intracoronary Doppler flow measurements were performed in a total of 212 patients who underwent coronary interventions because of significant epicardial stenosis using 0.014" Doppler flow wire (Cardiometrics, Inc, Mountain View, CA). Intracoronary bolus injection of adenosine (12 micrograms for the right coronary and 18 micrograms for the left coronary arteries) was used to induce hyperemic reaction. CFVR was registered as the ratio of average peak velocity during hyperemia (hAPV) to at baseline (bAPV). Successful coronary interventions either by percutaneous transluminal coronary balloon angioplasty (PTCA) or by stenting could significantly improve the CFVR. In 80 patients with PTCA, the bAPV elevated from 16.6 +/- 2.1 cm/s to 20.6 +/- 13.4 cm/s and hAPV from 30.1 +/- 15.9 cm/s to 45.2 +/- 17.7 cm/s (both p < 0.001) with PTCA and the CFVR increased from 1.94 +/- 0.78 to 2.58 +/- 0.87 correspondingly (p < 0.001). Significant elevation of coronary flow parameters were also found in 132 patients with subsequent stent implantation (bAPV from 15.3 +/- 6.7 cm/s to 18.7 +/- 9.1 cm/s, hAPV from 28.7 +/- 14.4 cm/s to 44.3 +/- 17.7 cm/s and CFVR from 1.90 +/- 0.70 to 2.59 +/- 0.87, all p < 0.001). Reduction of CFVR (< 3.0) after intervention still existed in 46 (61.3%) of 80 patients after PTCA and 88 (66.7%) of 132 patients after stenting. Moreover, CFVR < 3.0 were found in 50 (45.9%) of 109 reference vessels in patients with single vessel disease. Significant improvement of coronary flow velocity and coronary flow velocity reserve could be obtained after successful angioplasty. However, microvascualr dysfunction existed in a large proportion of patients either in normal reference vessels or in target vessels after interventions.

Purification of ribonucleotide reductase subunits Y1, Y2, Y3, and Y4 from yeast: Y4 plays a key role in diiron cluster assembly

Ribonucleotide reductases (RNRs) catalyze the conversion of nucleotides to deoxynucleotides. Class I RNRs are composed of two types of subunits: RNR1 contains the active site for reduction and the binding sites for the nucleotide allosteric effectors. RNR2 contains the diiron-tyrosyl radical (Y.) cofactor essential for the reduction process. Studies in yeast have recently identified four RNR subunits: Y1 and Y3, Y2 and Y4. These proteins have been expressed in Saccharomyces cerevisiae and in Escherichia coli and purified to approximately 90% homogeneity. The specific activity of Y1 isolated from yeast and E. coli is 0.03 micromol.min(-1).mg(-1) and of (His)(6)-Y2 [(His)(6)-Y2-K387N] from yeast is 0.037 micromol. min(-1).mg(-1) (0.125 micromol.min(-1).mg(-1)). Y2, Y3, and Y4 isolated from E. coli have no measurable activity. Efforts to generate Y. in Y2 or Y4 using Fe(2+), O(2), and reductant have been unsuccessful. However, preliminary studies show that incubation of Y4 and Fe(2+) with inactive E. coli Y2 followed by addition of O(2) generates Y2 with a specific activity of 0.069 micromol.min(-1). mg(-1) and a Y. A similar experiment with (His)(6)-Y2-K387N, Y4, O(2), and Fe(2+) results in an increase in its specific activity to 0.30 micromol.min(-1).mg(-1). Studies with antibodies to Y4 and Y2 reveal that they can form a complex in vivo. Y4 appears to play an important role in diiron-Y. assembly of Y2.

Intravascular ultrasound classification of atherosclerotic lesions according to American Heart Association recommendation

BACKGROUND

Intravascular ultrasound (IVUS) offers a new modality by which to image the vessel wall in high resolution. The aim of the study was to classify atherosclerotic lesions using IVUS according to American Heart Association (AHA) recommendation.

METHODS

IVUS was performed using a 20 or 30 MHz mechanically rotated catheter in 190 patients (aged from 35 to 75 years, mean 59 +/- 9 years) who presented with suspicion of coronary artery disease based on clinical examination.

RESULTS

Of the 190 patients, 49 (26%) (group A) were found to have normal or nearly normal coronary arteries, whereas the other 141 (74%) (group B) had significant angiographic stenosis (> 50% luminal narrowing). IVUS image interpretation was based on the recommendation of the Committee on Vascular Lesions of the Council on Atherosclerosis (AHA). In group A, a total of 822 segments were evaluated with IVUS; 444 (54%) were found to have plaque formation. Among these 444 segments, type II lesions were found in 145 (33%), type III lesions in 110 segments (25%), type IV and Va lesions in 169 segments (38%), and type Vb in 18 segments (4%). The severity of plaque area stenosis increased from type II to IV. In group B, only the most stenotic segments (n = 141) on angiography were selected for analysis. No significant differences were found among different lesion types with respect to the severity of plaque area stenosis. Type Vb and Vc lesions presented mainly, but not exclusively, as stable angina, whereas type VI lesions presented mainly as unstable angina. Some patients (12%) with stable angina had complicated lesions (type VIa-VIc).

CONCLUSIONS

It is now possible to use intravascular ultrasound to classify atherosclerotic lesions according to the AHA recommendations that were based on histological examination. Standardized reports of IVUS can now be based on these recommendations. Even in angiographically normal coronary arteries, advanced atherosclerotic lesions are found, explaining the potential risk of acute coronary syndromes in this group of patients. In patients with angiographically severe coronary disease, clinical symptoms correlate mainly with plaque characteristics, rather than with the severity of stenosis.

Corrective change of retinal thickness measured by optical coherence tomography and histologic studies

PURPOSE

To evaluate the correlation of retinal thickness between optical coherence tomography (OCT) images and histologic slides.

METHODS

Retinal thickness was measured in 16 rabbit retinal histologic slides. The same eyes had been previously measured by OCT for the comparison of results between two methods. Retinal thickness of each OCT image section was measured using both the manually assisted (requiring localization of reflectivity peaks by observer) and automated modes of the computer software.

RESULTS

Retinal thickness measured by OCT demonstrated a high degree of correlation with retinal histologic study. The automated method (Cc = 0.66, P < 0.01) was less reliable than the manually assisted one (Cc = 0.84, P < 0.001). The former had an error in 95% confidence interval, ranged between -0.71 and 11.09 microns. The latter had a less error, ranged from -2.99 to 5.13 microns.

CONCLUSION

OCT can quantitatively measure the retinal thickness. However, automatical identification of the reflective boundaries by computer may result in errors in some cases. To measure the retinal thickness by manually assisted mode can increase the accuracy.

New management of malignant glaucoma by phacoemulsification with posterior chamber foldable intraocular lens implantation

OBJECTIVE

To investigate the feasibility of phacoemulsification with posterior chamber foldable intraocular lens implantation in the management of malignant glaucoma.

PATIENTS AND METHODS

Fourteen patients with malignant glaucoma diagnosed in the Department of Glaucoma were enrolled in the study. 12 patients developed malignant glaucoma after filtration surgery. 1 developed after peripheral iridectomy. 1 patient developed malignant glaucoma without any clear cause. Cataract phacoemulsification was performed. Posterior chamber intraocular foldable lens was implanted in 10 cases of patients.

RESULTS

All 14 patients were cured with normal intraocular pressure, normal anterior chamber depth and increased visual acuity.

CONCLUSION

Phacoemulsification with posterior chamber foldable intraocular lens implantation is a good alternative in treating malignant glaucoma.

Worldwide ethnic distribution of the G protein beta3 subunit 825T allele and its association with obesity in Caucasian, Chinese, and Black African individuals

Recently, it was demonstrated that one allele (825T) of the gene encoding the G protein beta3 subunit (GNB3) is associated with hypertension in Germans. This study investigates a possible association with obesity in young male Germans, Chinese, and black South Africans with low, intermediate, and high 825T allele frequencies, respectively. In each of these three distinct cohorts, the 825T allele frequency was increased significantly in overweight (body mass index [BMI] > or =25 kg/m2) and obese individuals (BMI >27 kg/m2) compared to those with normal weight. The 825T allele frequencies in these three BMI groups were, respectively, 29.5, 39.3, and 47.7% in Germans, 46.8, 53.9, and 58.6% in Chinese, and 83.1, 87.7, and 90.9% in South Africans. In each of these three distinct groups, the 825T allele was significantly associated with obesity with odds ratios between 2 and 3. More urban than rural black Africans were overweight despite similar 825T allele frequencies in both populations, which underscores the role of both genetic and environmental factors. BP values in young male whites increased significantly with increasing BMI values but were independent of the C825T polymorphism, suggesting that hypertension associated with the 825T allele could be a consequence of obesity. Genotyping of 5254 individuals from 55 native population samples from Africa, the Americas, Europe, Asia, Australia, and New Guinea demonstrated highest 825T allele frequencies in black Africans (82%) and intermediate values in east Asians (47%). It is anticipated that high frequencies of the 825T allele in Africans and Asians may contribute to an obesity and hypertension epidemic if Westernization of lifestyles continues.

Differentiation of embryonic stem cells into neurons and retina-like structure in nude mice

PURPOSE

To investigate the intraocular growth and biological characteristics of mice embryonic stem cells in nude mice.

METHODS

Murine embryonic stem cells (D3 cell line) were cultured and maintained in an undifferentiated state in vitro, then transplanted into the anterior chamber of nude mice. Mophological and immunohistochemical examinations were implemented.

RESULTS

Two to three days after transplantation, yellow-white floating granules, sheets and masses were seen inside the anterior chamber and vitreous cavity, and enlarged gradually. 14-20 days later, the mice were executed. Morphological examination showed that there were undifferentiated cells and some round or polygonal differentiated cells in anterior chamber and vitreous cavity. The morphology of these differentiated cells were similar to that of the retina. The cells were highly positive in NSE staining.

CONCLUSION

The transplanted embryonic stem cells could grow in the eyes of nude mice with tendency to differentiate into neurons and retina-like structure.

The study of influencing factors on the growth characters of Sprague-Dawley rat retinal neurons in vitro

PURPOSE

To investigate the influencing factors in culturing Sprague-Dawley (S-D) rats retinal neurons in order to lay foundation for further experimental research.

MATERIALS AND METHODS

Retinal cells were plated on plastic plates and coverslips coated with poly-l-lysine or ethylene imine polymer for primary culture. The cultured cells were divided into following groups: 1. Culture medium changed every 2 to 3 days vs changed only once; 2. Cytosine arabinoside (Ara-C) added to the culture medium vs not added. The cells were observed and pictured under inverted phase contrast microscope. The cells were identified through immunocytochemistry.

RESULTS

The immunofluorescence showed that most of the cultured cells were neurons, among them were a few retinal ganglion cells. In the cultured group of which substrata coated with poly-l-lysine and culture medium added with Ara-c, the neurons intended to aggregate into clusters with relatively straight neurites. In the group of which substrata coated with ethylene imine polymer and medium added with Ara-c, the neurons grew dispersively with bent neurites. Both of them survived for 2 to 3 weeks. The cells which plated in the medium not added with Ara-c did not aggregate into clusters and survived longer than 4 weeks. In the group of which medium changed several times, the survival time of neurons was shorter than that in the medium changed only once.

CONCLUSIONS

The retinal neurons plated on the substrata coated with ethylene imine polymer are easy to observe because of its dispersive growth. It is not favorable for the growth of the neurons by changing culture medium many times. Ara-c may possibly have side effect on the growth of retinal neurons.

Parents' perceptions of randomization in pediatric clinical trials. Children Cancer Group

OBJECTIVES

The purpose of this study was to investigate parents' knowledge and perceptions about randomization in clinical trials for children with cancer, and to determine whether parents' decisions were influenced by demographic factors, randomization circumstances, the clinical characteristics of the child with cancer, or a combination.

MATERIALS AND METHODS

This study collected information from 192 parents of patients with various forms of childhood cancer who either accepted or refused randomization. A comparative case-control design was used. The Clinical Investigation Randomization Scale was administered to all participants. This scale included 32 questionnaire items (QIs) pertaining to randomization as well as a mixture of open-ended questions to obtain information about demographic and other factors.

RESULTS

A predictor model was developed that accurately predicted acceptance or refusal of randomization 87% of the time. Demographic information was found to have less influence than expected on parents' decisions regarding randomization. Knowledge deficits were found among both groups of parents, those who accepted and those who refused randomization.

CONCLUSIONS

What most distinguished parents who refused from those who accepted randomization was not their knowledge and information about randomized clinical trials. By far, the majority of QIs that accurately predicted acceptors and refusers involved parents' beliefs, values, and perceptions. Further research is needed to determine interventions that may enable the healthcare team to provide information and decisional support most effectively to improve the informed consent process.

Does remodeling occur in the diseased human saphenous vein bypass grafts? An intravascular ultrasound study

BACKGROUND

Coronary artery remodeling is a common phenomenon in human atherosclerotic arteries. Controversies exist concerning the presence of absence of the remodeling process in diseased human coronary saphenous vein bypass grafts. The purpose of the study was to observe the vessel and lumen dimensions in patients who had undergone saphenous vein grafting with intravascular ultrasound to find out whether the remodeling process exists in the diseased human saphenous vein bypass grafts.

METHODS

A total of 43 saphenous vein bypass grafts from 43 patients (39 males, 4 females, mean age 63+/-8 years); 1-16 years (mean 9.3+/-4.0 years) after grafting, who had not undergone previous catheter intervention, were studied using intravascular ultrasound. The vessel, lumen and plaque area were measured at the lesion segment as well as in the proximal and distal reference segments. The percent stenosis was calculated.

RESULTS

In 43 bypass grafts having severe stenosis before intervention, plaque was eccentric in 69.4% and concentric in 30.6%. No calcification was detected in 75% cases and 25% cases has mild-moderate intimal calcification. The vessel area in the lesion segment was 19.0+/-9.7 mm2, significantly larger than the proximal reference segment 12.8+/-4.0 min2 as well as the distal reference segment 12.9+/-3.6 mm2 (p < 0.001). It was also larger than that of the average area of the proximal and distal reference segments (p < 0.001). The vessel area increased in accordance with plaque area (p < 0.001). A weak relationship existed between vessel area and percent stenosis (r = 0.37, p = 0.04).

CONCLUSION

In contrary to previous findings, diseased human saphenous vein bypass grafts undergo focal compensatory enlargement (remodeling) in the presence of plaque formation. The underlying mechanism is probably similar to that in de novo atherosclerosis.

Central venous catheter use and the risk of infection in children with acute lymphoblastic leukemia: a report from the Children's Cancer Group

PURPOSE

To describe patterns of central venous catheter (CVC) use and determine the risk of infection associated with a catheter in children with acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

Children with ALL (n = 1934), participating in Children's Cancer Group studies for good-prognosis ALL (CCG-1881) and intermediate-risk ALL (CCG-1891) were evaluated in a retrospective case-control study. The presence of a catheter and the occurrence of infectious complications were recorded after each treatment phase.

RESULTS

Young age and enrollment in the intermediate-risk study were associated with higher rates of catheter use. During each of the first four phases of therapy, the adjusted risk of infection was two- to fourfold higher when a catheter was in place. The proportion of patients with infection during the first four phases of therapy was 2.6 times higher with a CVC (14.4% versus 5.7%). Catheter use was associated with significantly increased hospitalization rates during induction, consolidation, and interim maintenance, but not during delayed intensification. A catheter did not significantly increase the risk of fever during neutropenia.

CONCLUSION

The presence of a CVC increases the risk of infection during the early phases of low-intensity therapy for ALL.

Monoclonal antibodies, antigens and molecular diagnostics: a practical overview

The development of monoclonal antibody-based immunochemical assays to measure antibodies, antigens and small molecules, such as drugs, ushered in a revolution in modern diagnostic medicine. The impact of monoclonal antibodies on diagnostic imaging technologies and therapeutic regimes was equally dramatic. Additionally, the application of immunological techniques to the biochemical research lab was partially responsible for the exponential growth in our understanding of human physiology, biochemistry and genetics. Monoclonal antibody technology is limited, however, by the manner in which antigen-antibody interactions can be controlled and by the ability to consistently produce antibodies with appropriate affinity and specificity. Recent advances in recombinant antigen preparation and antibody engineering have been used to enhance the applications of this technology. In this review, current strategies to generate and engineer monoclonal antibodies as well as their clinical applications are summarized. A brief review of molecular diagnostics and its future trend is also included.

Malignant transformation of an optic disk melanocytoma

PURPOSE

To report a case of malignant transformation of an optic disk melanocytoma with a second melanocytoma in the ciliary body.

METHODS

Clinical data including visual acuity, visual fields, color fundus photographs, fluorescein angiogram, and ultrasonogram and histopathologic studies of this case were reviewed.

RESULTS

The right eye of a 65-year-old white woman was diagnosed with melanocytoma of the optic nerve. Four years later, the tumor became significantly larger. The best-corrected visual acuity declined from 20/40 to counting fingers and the size of the tumor increased fourfold in 2 years. The right globe was enucleated. Histopathologic studies demonstrated moderately pigmented spindle-B malignant melanoma cells adjacent to and within a population of large, polyhedral, heavily pigmented melanocytoma cells that extended to the lamina cribrosa and optic nerve. There was also a deeply pigmented melanocytoma in the ciliary body.

CONCLUSION

This is a rare case of malignant melanoma transformed from an optic disk melanocytoma. Periodic follow-up of the patient with optic disk melanocytoma is necessary.

[Effect of N-methyl-D-aspartate and dexamethasone on apoptosis of rat cultured retinal ganglion cells]

PURPOSE

To investigate the effect of N-methyl-D-aspartate(NMDA) and Dexamethasone on cultured rat retinal ganglion cells (RGCS).

METHODS

RGCs were obtained from 1-3 days old SD rats. In two groups, exposure of cocultured ganglion cells to N-methyl-D-aspartate (20-500 mumol/L) lasted for 24 hours. Apoptotic cells were identified by Hochest 33258 in one group; In another group, 0.4% Trypan blue dye was added. Cells excluding the dye were counted, and the survival rate of cells was determined by the ratio of the excluding cells in the experiment over in the control; Cocultured RGCs and purified RGCs were exposed to Dexamethasone(1 x 10(-4), 1 x 10(-5) and 1 x 10(-6) mol/L). After 24 hours, apoptotic cells were identified by Hochest33258.

RESULT

Cocultured RGCs showed distinct morphological appearance of apoptotic cells when they were exposed to NMDA. The survival rate of cells was dose-related to the concentration of NMDA. Cocultured RGCs didn't show typical apoptotic appearance at 24 hours after exposure to Dexamethasone. But purified RGCs did so, even in the control group.

CONCLUSION

NMDA has the effect of inducing cocultured RGCs apoptosis. Dexamethasone had no this effect on RGCs. Without additional neurotrophic factors, purified RGCs may become apoptotic cells when cultured in vitro for 24 hours.

Screening of ruptured plaques in patients with coronary artery disease by intravascular ultrasound

AIM

To visualise the characteristics of ruptured plaques by intravascular ultrasound (IVUS) and to correlate plaque characteristics with clinical symptoms to establish a quantitative index of plaque vulnerability.

METHODS

144 consecutive patients with angina were examined using IVUS. Ruptured plaques, characterised by a plaque cavity and a tear on the thin fibrous cap, were identified in 31 patients (group A), of whom 23 (74%) presented with unstable angina. Plaque rupture was confirmed by injecting contrast medium filling the plaque cavity during IVUS examination. Of the patients without plaque rupture (group B, n = 108), only 19 (18%) had unstable angina.

RESULTS

No significant differences were found between groups A and B in relation to plaque and vessel area (p > 0.05). Mean (SD) per cent stenosis in group A was less than in group B, at 56.2 (16.5)% v 67.9 (13.4)%; p < 0.001. Area of the emptied plaque cavity in group A (4.1 (3.2) mm2) was larger than the echolucent zone in group B (1.32 (0.79) mm2) (p < 0.001). The plaque cavity to plaque ratio in group A (38.5 (17.1)%) was larger than the echolucent area to plaque ratio in group B (11.2 (8.9)%) (p < 0.001). The thickness of the fibrous cap in group A was less than in group B, at 0.47 (0.20) mm v 0.96 (0.94) mm; p < 0.001.

CONCLUSIONS

Plaques seem to be prone to rupture when the echolucent area is larger than 4.1 (3.2) mm2, when the echolucent area to plaque ratio is greater than 38.5 (17.1)%, and when the fibrous cap is thinner than 0.7 mm. IVUS can identify plaque rupture and vulnerable plaques. This may influence patient management and treatment.

Cytogenetic studies of infant acute lymphoblastic leukemia: poor prognosis of infants with t(4;11) - a report of the Children's Cancer Group

Infants less than 1 year of age at diagnosis of acute lymphoblastic leukemia (ALL) have a poor prognosis, which has been attributed primarily to a breakpoint in chromosomal band 11q23 or the MLL gene. Most infants with an 11q23 breakpoint have a t(4;11)(q21 ;q23). We studied the cytogenetics of the leukemia cells of 56 infants on CCG-1883, a single-arm clinical treatment protocol for infant ALL. Twenty-one patients had t(4;11)(q21;q23), seven had other rearrangements with breakpoints in 11q23 (other 11q23), 16 had normal chromosomes, two had t(1;19)(q32;p13), one had >50 chromosomes, and nine had non-recurring structural abnormalities. To determine whether there is a difference in outcome for infants with t(4;11), other 11q23 and the remaining patients, we compared event-free survival (EFS) and other clinical and laboratory features of the above infants. Infants without t(4;11) and those with other 11q23 rearrangements had significantly better EFS than those with t(4;11) (P= 0.007 and P= 0.02, respectively). t(4;11) correlated with age less than 6 months and with CD10 negativity, both of which also were poor prognostic indicators. After adjustment for age, there was still a significant difference in EFS between patients with t(4;11) and those with other 1lq23 rearrangements (P=0.02), and between patients with t(4;11) and those without t(4;11) (P=0.04). Among CD10 negative patients, t(4;11) was associated with a worse EFS (P=0.01). Multivariate analysis showed that after adjusting for a variety of clinical and laboratory features, t(4;11) was the most important prognostic factor for poor outcome, and patients with other 11q23 rearrangements had as good an outcome as the remaining patients without t(4;11).

[The experimental research of purification and character of cultured retinal ganglion cell]

OBJECTIVE

To establish a cell line and purification model of retinal ganglion cells (RGCs) in vitro.

METHOD

RGCs from Sprague Dawley neonatal rats (postnatal 1 - 3 days) were cultured in basal medium eagle (BME) basal medium. The growth regularity of RGCs in vitro was observed under phase-contrast microscope. RGCs were purified by Thy 1.1 with FITC antibody and detected under fluorescent microscope and phase-contrast microscope.

RESULTS

Higher density of retinal cells and tectal extract facilitate cultured RGCs to survive. The purification rate of retinal ganglion cells in the experiment arrived at 95 percent.

CONCLUSION

Cytokine and trophic factors from other cells in the retina and tectal extract can promote RGCs to survive, and they can be purified by Thy 1.1 antibody.

Augmented alpha-adrenergic constriction of atherosclerotic human coronary arteries

BACKGROUND

Although adrenergic activation plays a major role in the initiation of experimental myocardial ischemia, the significance of alpha-adrenergic coronary constriction in humans has been questioned. The present study assessed the impact of selective alpha-adrenergic receptor activation in patients with normal or atherosclerotic coronary arteries.

METHODS AND RESULTS

In 39 patients, coronary blood flow (CBF, mL/min) was determined from combined angiography and Doppler measurements. In 8 patients with normal coronary arteries (group 1) and 9 with single coronary artery stenosis (group 2), doses of 1, 2.5, 5, and 10 mg IC of the alpha1-agonist methoxamine (M) were injected. Identical doses of the alpha2-agonist BHT933 (B) were injected in 8 patients with normal coronary arteries (group 3) and 8 with single stenosis (group 4). In 6 additional patients with single stenosis (group 5), aortocoronary sinus lactate differences were measured in response to M and B. CBF remained unchanged in group 1. In contrast, CBF was decreased dose-dependently in group 2, with a maximum at 10 mg M (39.0+/-9.4 versus 15.2+/-7.0). In groups 3 and 4, CBF was also decreased dose-dependently, with a maximum at 10 mg B (63.3+/-24.8 versus 49. 1+/-27.9 and 41.5+/-19.0 versus 12.7+/-8.0, respectively). In group 5, there was more net lactate production with B than with M (-0. 34+/-0.11 versus -0.04+/-0.09 mmol/L).

CONCLUSIONS

In normal coronary arteries, alpha1-adrenergic activation does not reduce CBF, whereas alpha2-adrenergic activation reduces CBF by microvascular constriction. Both alpha1- and alpha2-adrenergic epicardial and microvascular constriction are augmented by atherosclerosis and can induce myocardial ischemia.