[Analysis of the lineshape of laser frequency modulation]

In this paper, we analyze the dependence of the output signal spectral lineshape and intensity on the modulation, waveform and modulation index in first- and second-harmonic detection of triangle modulation, square demodulation and saw modulation square demodulation. The signal lineshape in the case of saw modulation, square demodulation is quite different from, whereas the signal lineshape in the case of triangle modulation, square demodulation is similar to that in traditional sine modulation, sine demodulation. Experiments of tunable IR laser frequency modulation absorption spectrum of methane are also done to verify the theoretical analysis. Then we reach a conclusion; the lineshape and intensity of frequency modulation spectrum can be influenced by modulation waveform, demodulation waveform and modulation index. Calculation results can be used to choose better experimental parameters and optimize experimental designs.

Eradication of posterior capsule opacification: documentation of a marked decrease in Nd:YAG laser posterior capsulotomy rates noted in an analysis of 5416 pseudophakic human eyes obtained postmortem

OBJECTIVE

(1) To report the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser posterior capsulotomy rate (%) of eight rigid and foldable intraocular lens (IOL) designs in a series of 5416 pseudophakic human eyes obtained postmortem, accessioned in our center between January 1988 and January 2000. (2) To identify factors that are instrumental in reducing the incidence of posterior capsule opacification, (PCO, secondary cataract) and hence the need for Nd:YAG laser posterior capsulotomy.

DESIGN

Comparative autopsy tissue analysis.

PARTICIPANTS

A total of 5416 globes with posterior chamber intraocular lens (PC-IOLs) obtained postmortem received from Lions Eye Banks between 1988 and 2000.

METHODS

Miyake-Apple posterior photographic technique. Special reference was given to the presence or absence of Nd:YAG laser posterior capsulotomy orifice on the posterior capsule of each eye.

MAIN OUTCOME MEASURES

The Nd:YAG laser posterior capsulotomy rate (%) as of January 2000 was documented. In addition, the Nd:YAG laser posterior capsulotomy rate for each lens was plotted on a monthly basis for the same period, creating a computerized trend or "timeline" for each IOL style.

RESULTS

Relatively high Nd:YAG laser posterior capsulotomy rates ranging from 20.3% to 33.4% were noted with four relatively older designs (high incidence of implantation between 1988 and the early 1990s). Four modern foldable IOLs manufactured from silicone and acrylic materials had significantly lower Nd:YAG laser posterior capsulotomy rates ranging from 0.9% (Alcon Acrysof) to 17.1%. The difference in Nd:YAG rates among the eight IOL designs was found to be significant (P < 0.0001, chi-square test). Comparing foldable versus rigid designs, the foldable IOLs were associated with a much lower Nd:YAG laser posterior capsulotomy rate (14.1% vs. 31.1%).

CONCLUSIONS

By use of the six factors regarding surgical technique and IOL choice described in this article, we strongly believe that the overall incidence of PCO and hence the incidence of Nd:YAG laser posterior capsulotomy is now rapidly decreasing from rates as high as 50% in the 1980s to early 1990s. Surgical tools and IOLs are now available to bring these rates down to single digits. Careful application and use of these tools by surgeons can genuinely lead in the direction of virtual eradication of secondary cataract, the second most common cause of visual loss worldwide.

Endogenous production of protoporphyrin IX induced by 5-aminolevulinic acid in leukemia cells

AIM

To explore the photosensitization of 5-aminolevulinic acid (ALA) in myeloid leukemia cell line.

METHODS

Using the technique of fluorescence spectra, the A LA induced protoporphyrin IX (Pp IX) was measured in myeloid leukemia JCS cells. Cofocal laser scanning microscopy (CLSM) combined with fluorescence organelle probe was used to detect the localization of Pp IX in JCS cells at the subcellular levels. MTT assay was used to measure the cell survival after light irradiation.

RESULTS

ALA successfully produced endogenous PpI X in leukemia JCS cells. PpIX was observed to be distributed in the cytoplasm and mitochondria was exhibited as the one of binding sites of PpIX. As a photosensitizer, PpIX initiated photodynamic reaction after light irradiation and effectively photodamaged leukemia cells.

CONCLUSION

ALA-based photosensitization could be used for inactivation of leukemia cells.

Linkage analysis of the 5q31-33 candidate region for asthma in 240 UK families

Atopy and asthma are complex genetic diseases resulting from the interactions of a number of genetic and environmental factors. We had previously reported allelic association between the IL9 marker on chromosome 5q31-33 and atopy. In order to further investigate the role of susceptibility genes on 5q31-33 in the development of atopy and asthma we have studied 240 UK families comprising 131 families selected at random, 60 multiplex families with affected sib pairs, and 49 single proband nuclear families. Polymorphic markers on 5q31-33 were genotyped and both single and multipoint linkage analysis was undertaken using the BETA program. We have used both affection status and quantitative scores for atopy and asthma for phenotypic variables, combining data into scores for asthma and atopy. The strongest suggestion of linkage using multipoint analysis was centred around D5S410 with a maximum Lod of 1.946 at location 171.3 cM and a standard error of 3.3 for the asthma quantitative score. There was no evidence of linkage with atopy, the atopy quantitative score or total serum IgE.

Anatomical study of the synovial plicae of the hip joint

Observations and measurements of the synovial plicae of the hip joints were made on 63 embalmed cadavers. The cadavers were divided equally among three age groups (fetuses, children, and adults). Our observations showed that the plicae appeared in two forms (flat and villous) and were mainly confined to the external surface of the lower medial part of the acetabular labrum (labral plicae), the base of the ligament of the head of the femur (ligamental plicae), and along the reflecting line of the synovial membrane on the base of the femoral neck (neck plicae). The ligamental plicae were well padded with a fibroelastic pad of fat filling the acetabular fossa, and the neck plicae were far away from the articular surfaces of the joint; as a result, neither was likely to be injured or entrapped during joint movements. The labral plicae were larger than the ligamental or neck plicae and had an incidence of 73.8% in the fetal group. The fetal plicae were found only after the fetal age of 5 months. In nine cases of the child and adult groups, the labral plicae extended between the articular surface of the femoral head and the lower part of the acetabulum during medial rotation of the thigh. When the thigh was rotated laterally, the plicae in six of the same cases could be returned to their original positions. In the remaining three cases, there was continual impingement.

Pycnogenol protects vascular endothelial cells from beta-amyloid-induced injury

The neuropathological hallmarks of Alzheimer's disease (AD) are senile plaques, cerebrovascular beta-amyloidosis, neurofibrillary tangles, and selective neuronal loss. Beta-amyloid (Abeta) has been shown to cause vascular damage mediated by generation of reactive oxygen species and this damage is considered an early event in the development of AD. In this study, we determined the effect of pyenogenol, a potent antioxidant phytochemical, on Abeta-induced cellular injury. Pulmonary artery endothelial cells (PAEC) were exposed to Abeta for 24 h. Cell injury was assessed by measuring cell viability with methylthiazol tetrazolium (MTT) assay, and by determining the release of intracellular lactate dehydrogenase (LDH). Lipid peroxidation products of PAEC were determined by measuring thiobarbituric acid-reactive substances (TBARS). Exposure of PAEC to Abeta resulted in a decrease in cell viability, an increase of LDH release indicating membrane damage, and an elevated level of TBARS. Preincubation of PAEC with pycnogenol significantly minimized these changes. This study demonstrated that pycnogenol can protect vascular endothelial cells from Abeta-induced injury. The data suggest that pycnogenol may be useful for the prevention and/or treatment of vascular or neurodegenerative diseases associated with Abeta toxicity.

Pycnogenol inhibits tumor necrosis factor-alpha-induced nuclear factor kappa B activation and adhesion molecule expression in human vascular endothelial cells

The transcriptional regulatory protein nuclear factor kappa B (NF-kappa B) participates in the control of gene expression of many modulators of inflammatory and immune responses, including vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). The heightened expression of these adhesion molecules has been reported to play a critical role in atherosclerosis, inflammation, ischemic vascular disorders, diabetes, and cancer metastasis. In the present study, we investigated the effect of pycnogenol, an antioxidant phytochemical, on the activation of NF-kappa B and the induction of VCAM-1 and ICAM-1 in tumor necrosis factor (TNF)-alpha-treated human umbilical vein endothelial cells (HUVECs). Gel-shift analysis of HUVEC demonstrated that pretreatment with pycnogenol exhibited a concentration-dependent suppression of TNF-alpha-induced activation of NF-kappa B. Induction of VCAM-1 and ICAM-1 surface expression by TNF-alpha was dose-dependently reduced by pycnogenol. TNF-alpha significantly increased the release of superoxide anion and hydrogen peroxide from HUVECs. Pycnogenol dose-dependently inhibited their release. The ability of pycnogenol to inhibit NF-kappa B activation and VCAM-1 and ICAM-1 expression suggests that this phytochemical may play an important role in halting or preventing the atherogenic process.

Anterior capsule opacification: a histopathological study comparing different IOL styles

OBJECTIVE

To compare the degree of anterior capsule opacification (ACO) in human eyes obtained post-mortem containing various rigid and foldable posterior chamber intraocular lens (PC-IOL) designs.

DESIGN

Comparative autopsy tissue study with clinicopathologic correlations.

MATERIALS

Four hundred sixty human globes containing the following PC-IOL styles were analyzed: (1) one-piece polymethylmethacrylate (PMMA) optic-PMMA haptic (n = 50), (2) one-piece silicone-plate IOL, large hole (n = 40), (3) one-piece silicone-plate IOL, small hole (n = 67), (4) three-piece PMMA optic-PMMA/Prolene haptic (n = 51), (5) three-piece acrylic optic-PMMA haptic (n = 96), (6) three-piece silicone optic-PMMA haptic (n = 24), (7) three-piece silicone optic-polyimide haptic (n = 40), and (8) three-piece silicone optic-prolene haptic (n = 92).

TESTING

The globes were sectioned in the equatorial plane for gross examination and then processed through paraffin; sectioned, and stained with hematoxylin-eosin, periodic acid-Schiff, and Masson's trichrome stains; and examined by light microscopy.

MAIN OUTCOME MEASURES

Anterior capsule opacification was scored in each eye by grading the histologic sections from 0 to III, according to the amount (thickness) of proliferative tissue and cells measured in sagittal sections on the inner surface of the anterior capsule at the capsulorhexis margin.

RESULTS

The difference among the eight groups was significant (P < 0.0001). Mean ACO scores were highest with the large and small hole one-piece silicone-plate lenses (1.77 +/- 0.86 and 1.28 +/- 0.77, respectively). The lowest mean score was observed in the group of three-piece acrylic optic-PMMA haptics lenses (0.51 +/- 0.52).

CONCLUSIONS

Our results confirm previous clinical observations that the rate of ACO is relatively high with plate-haptic silicone IOLs. The lowest rate was noted with the three-piece acrylic optic-PMMA haptic IOL. The IOL design and IOL material are significant factors in the development of ACO.

Creating cataracts of varying hardness to practice extracapsular cataract extraction and phacoemulsification(2)

We describe a method to harden the nucleus of crystalline lenses in postmortem human globes by intralenticular injection of a mixture of paraformaldehyde and glutaraldehyde (Karnovsky's solution). Evaluation of the nuclear manipulations, using the Miyake-Apple posterior video/photographic technique, shows that the method provides suitable specimens for practicing extracapsular cataract extraction and phacoemulsification.

Interlenticular opacification: clinicopathological correlation of a complication of posterior chamber piggyback intraocular lenses

PURPOSE

To present a clinicopathological correlation of 2 pairs of piggyback posterior chamber intraocular lenses (PC IOLs) explanted because of opacification between the lens optics.

SETTING

Gayton Health Center, Eyesight Associates of Middle Georgia, Warner Robins, Georgia, and Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.

METHODS

Two pairs of piggyback AcrySof lenses were explanted from 2 patients with significant visual loss related to opacification between the optics. They were submitted for pathological analysis. Gross and histopathological examinations were performed, and photomicroscopy was used to document the results.

RESULTS

Gross examination showed accumulation of a membrane-like white material between the lenses. Histopathological examination revealed that the tissue consisted of retained/proliferative lens epithelial cells (bladder cells or pearls) mixed with lens cortical material.

CONCLUSION

Piggyback PC IOLs were explanted in 2 cases because of a newly described complication, interlenticular opacification. Three surgical means may help prevent this complication: meticulous cortical cleanup, especially in the equatorial region; creation of a relatively large continuous curvilinear capsulorhexis to sequester retained cells peripheral to the IOL optic within the equatorial fornix; insertion of the posterior IOL in the capsular bag and the anterior IOL in the ciliary sulcus to isolate retained cells from the interlenticular space.

Surgical prevention of posterior capsule opacification. Part 2: Enhancement of cortical cleanup by focusing on hydrodissection

PURPOSE

To experimentally analyze the role and efficacy of hydrodissection in achieving maximal cortical cleanup.

SETTING

Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, USA.

METHODS

Phacoemulsification and irrigation/aspiration were performed in 10 pairs of human eyes (20 eyes) obtained postmortem. Ten eyes had previous hydrodissection and 10 eyes, no hydrodissection. The time (seconds) required for complete lens substance removal in each procedure was measured. In addition, a qualitative evaluation of difficulty of surgery was noted.

RESULTS

Phacoemulsification required 28.6% less time in eyes with previous hydrodissection than in those without. Irrigation/aspiration time was reduced by 50.9% when hydrodissection was performed. The total time of each procedure required for complete evacuation of the capsular bag was reduced by an average of 37.7% in eyes with hydrodissection. Furthermore, qualitatively the procedure was far easier, less stressful, and caused less posterior capsule stress or rupture when copious hydrodissection was performed.

CONCLUSIONS

Hydrodissection enhances the general safety and efficiency of cortical cleanup, especially at 12 o'clock. Hydrodissection is the best available, practical, immediately implementable, and inexpensive means to help remove equatorial E-cells and thus alleviate the incidence of posterior capsule opacification.

Surgical prevention of posterior capsule opacification. Part 1: Progress in eliminating this complication of cataract surgery

PURPOSE

To evaluate over almost 2 decades the success of a component of cataract surgery that represents a critical step in reducing the incidence of posterior capsule opacification (PCO); namely, the efficacy of cortical cleanup.

SETTING

Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, USA.

METHODS

Accessioned from the early 1980s to 1997, 3320 eyes obtained postmortem with posterior chamber intraocular lenses were analyzed with respect to formation of a postoperative Soemmering's ring. This anatomic lesion, the precursor of clinical PCO, represents an important and measurable indication of the quality of cortical cleanup. Its formation was documented using Miyake-Apple posterior photographic analysis.

RESULTS

The quality and thoroughness of cortical cleanup and overall effectiveness in eliminating retained and/or regenerating cortical cells, as measured by scoring of Soemmering's rings, showed virtually no net change since the early 1980s. The intensity of Soemmering's ring was higher in the most recent specimens than in those in the early 1980s.

CONCLUSION

The results indicate that renewed attention to cortical cleanup in cataract surgery is warranted for significant reduction in incidence or the elimination of PCO. More attention to the hydrodissection (cortical cleaving hydrodissection) step of the procedure is likely a practical, immediately implementable, and inexpensive remedy.

[The effective dielectric function of porous SiO2 glass]

In this paper, we discussed the effective dielectric function of porous SiO2 glass with pore size 7.5 nm. We briefly discussed different formulae proposed by different theoretical models of porous systems, and compared the relationship of effective dielectric functions changing with different porosity of porous SiO2 of each formula. Through comparing the experimental spectra and the theoretical spectra of each formula, we found the equation ln epsilon e = theta 1 ln epsilon 1 + theta 2 + theta 2 ln epsilon 2 best indicates the effective dielectric function of porous SiO2. This work is helpful in selecting special absorption materials.

Surgical prevention of posterior capsule opacification. Part 3: Intraocular lens optic barrier effect as a second line of defense

PURPOSE

To emphasize an important aspect of preventing posterior capsule opacification (PCO), the barrier effect established by the optic of a posterior chamber intraocular lens (PC IOL), and present a new classification regarding capsular bag status after extra-capsular cataract extraction, including phacoemulsification.

SETTING

Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.

METHODS

This analysis included 150 consecutive eyes obtained postmortem with United States-manufactured PC IOLs including (1) poly(methyl methacrylate), (2) silicone, and (3) hydrophobic acrylic designs that were accessioned in the Center from September 1995 to January 1, 1998. Gross photographs from behind (Miyake-Apple views) were taken and serial histologic sections prepared.

RESULTS

Microscopic analysis of the 150 eyes showed that the morphologic appearance of the capsular bag could be grouped into 2 categories: (1) those with little or no evidence of retained cortical material and cells, and (2) those with retained cortical material and cells in which a Soemmering's ring formed. With the latter, when a distinct barricade to cellular migration created by the IOL optic was noted, 2 discrete configurations occurred, depending on the different geometries of the optic components. With a classic biconvex optic with a curved and tapered edge, in many instances some ingrowth of cells proceeded posteriorly around the edge of the IOL optic in the direction of the central axis. With a lens optic that had a squared, truncated, and relatively thick edge, there was often abrupt termination of cells at the peripheral edge of the optic. The posterior capsule subtending the entire optic zone was therefore relatively or totally cell free.

CONCLUSIONS

The barrier effect of the IOL optic appears to be of critical importance in retarding ingrowth of cells, functioning as a second line of defense when cortical cleanup is incomplete. Analysis of PC IOLs obtained postmortem showed that a square, truncated optic edge seemed to provide the maximum impediment to cell growth behind the IOL optic.

Ginkgo biloba inhibits hydrogen peroxide-induced activation of nuclear factor kappa B in vascular endothelial cells

The present study determined the effects of Ginkgo biloba extract (GBE) on the activation of nuclear factor kappa B (NF-kappaB) and the level of hydrogen peroxide (H2O2) in bovine pulmonary artery endothelial cells (PAEC). H2O2 showed a concentration-dependent activation of NF-kappaB. GBE demonstrated a concentration-dependent suppression of NF-kappaB activated by H2O2. GBE directly scavenged H2O2 in a cell-free system; it also decreased H2O2 levels in PAEC. These results suggest that the inhibitory effect of GBE on H2O2-induced NF-kappaB activation may be caused by its scavenging and suppression of H2O2. Our experiments demonstrate that GBE can inhibit NF-kappaB activation induced by H2O2 and may thus be effective for the prevention or treatment of atherosclerosis and other disorders related to NF-kappaB activation.

[Antihypertensive study of xingnao qingxuan recipe]

OBJECTIVE

To observe the effect of decreasing blood pressure of Xingnao Qingxuan Casuples.

METHOD

The blood pressure in normal and anesthetised cats was examined with direct method, the blood pressure in the conscious SHR was obtained by indirect method.

RESULTS

Duodenuos administration(id) of XQC of 2.8 g/kg produced a decrease of blood pressure in normal cats; XQC of 1.4, 2.8 and 5.6 g/kg once a day for 14 days produced a dose-dependent reduction of blood pressure in SHR, 3-4 days after administration the blood pressure returned to the level before but the change was not significant. With gastric administration of XQC of 2.8 and 5.6 g/kg for 3 times, the incubation period of eyeball tremor induced by chloroform by dropping into the ear was prolonged by 14.4% and 13.0%, and the keeping time shortened by about 33.3% and 23.3% respectively. Brain basic arterial spasm induced by KCl or 5-HT in dog was relaxed obviously by XQC in vitro experiment.

CONCLUSION

XQC has the effect of reducing blood pressure resisting dizziness, which is related to the diastole of brain blood vessel.

[Transplantation of neural retina after photic injury of retina in mice]

OBJECTIVE

To examine the possibility of retinal photoreceptors rescued after photic injury by allogeneic neural retinal transplantation.

METHODS

The retinal photic injury model was established by a light-damage trunk designed by ourselves. After photo-illumination, 60 mice were divided into two groups: Group I (n = 20) was the photic injury group and group II (n = 40), the retinal transplantation group; then group II was subdivided into II(A) (n = 20) and II(B) (n = 20) subgroups. External approach for neural retinal transplantation was performed at 24hr (group II(A)) and day 7 (group II(B)) after photic injury respectively. The recipients were sacrificed at day 6, day 12, day 18 and day 30 post-operatively to examine whether the graft could rescue the injured retinal photoreceptors.

RESULTS

In group I, the inner and outer segment showed edema, disorganization and vesiculation, the outer nuclear layer became very thin and disorganized, and the cell nuclear chromatin showed pyknosis and margination. In group II, the graft survival rate in group II(A) was 50% (10/20) and in group II(B) was 80% (16/20), the difference being significant (chi(2) = 3.956, P < 0.05). Among the graft survival samples, we compared the rescue rate of photoreceptors between group II(A) 40% (4/10) and group II(B) 50% (8/16), the difference being not significant (P = 0.702).

CONCLUSION

The retinal photic injury may result in photoreceptor degeneration that can be rescued by retinal transplantation, and the successful rate of the transplantation performed at day 7 is higher than that at 24-hr after injury.

Update on fixation of rigid and foldable posterior chamber intraocular lenses. Part II: Choosing the correct haptic fixation and intraocular lens design to help eradicate posterior capsule opacification

PURPOSE

Posterior capsule opacification (PCO) is one of the most common complications of cataract surgery, and there is an urgent need to reduce its incidence. Its main treatment, neodymium:YAG (Nd:YAG) laser posterior capsulotomy, may be associated with significant morbidity and is expensive. In this study, the authors ascertain the effect of posterior chamber intraocular lens (PC-IOL) fixation and various IOL designs (rigid polymethyl methacrylate [PMMA] optic and small-incision foldable designs) on the pathogenesis of PCO.

DESIGN

Prospective analysis of pseudophakic eyes obtained postmortem.

PARTICIPANTS

A total of 3493 eyes with PC-IOLs obtained postmortem and received between 1984 and 1998.

METHODS

Miyake-Apple posterior photographic technique.

MAIN OUTCOME MEASURES

Peripheral Soemmering's ring, central PCO in the visual axis, and eyes that have had Nd:YAG laser posterior capsulotomy were analyzed and scored, and these findings were correlated with the type of fixation and IOL design.

RESULTS

The degree of formation of peripheral Soemmering's ring was not influenced by IOL fixation. The acrylic design revealed relatively low Soemmering's ring scores. In contrast, central PCO and Nd:YAG laser capsulotomy scores were consistently influenced by fixation. The scores were significantly lower in eyes with in-the-bag fixation. The bag-bag fixated acrylic-PMMA design and the three modern silicone IOL designs analyzed in this study had less central PCO and lower posterior capsulotomy scores than did the PMMA IOLs.

CONCLUSIONS

The formation of peripheral PCO (the Soemmering's ring), the precursor of clinically significant, vision-threatening PCO, is not significantly influenced by the haptic fixation pattern. It is much more dependent on the quality and thoroughness of surgical cortical cleanup. Reduction of Soemmering's ring is an important goal because the retained regenerative cortical cells within this lesion are the cells of origin of PCO. The acrylic IOL design was associated with a lessor amount of peripheral Soemmering's ring as compared with all other designs. In sharp contrast to peripheral PCO, fixation of the IOL was a highly significant factor affecting the formation and quantity of central PCO-the clinically significant opacity behind the IOL optic, measured in this series either by scoring an intact retro-optical membrane or by documenting the presence of a Nd:YAG laser posterior capsulotomy orifice. The quantity of central PCO was consistently much lower in eyes with in-the-bag fixated IOLs compared with lenses with one or both haptics out of the bag. This is best explained by the fact that secure in-the-bag fixation positions the IOL optic in the best possible position to create a barrier effect. The lowest PCO rates were generally noted with the acrylic and modern silicone IOL designs.

Update on fixation of rigid and foldable posterior chamber intraocular lenses. Part I: Elimination of fixation-induced decentration to achieve precise optical correction and visual rehabilitation

PURPOSE

Realizing that precise posterior chamber intraocular lens (PC-IOL) centration is needed to consistently achieve good optical results and visual rehabilitation after modern cataract surgery, the authors assessed the status and success rate of lens haptic fixation and its correlation with lens optic centration-decentration in a large series of eyes with PC-IOLs obtained postmortem.

DESIGN

Prospective analysis of pseudophakic eyes obtained postmortem.

PARTICIPANTS

A total of 3493 human eyes obtained postmortem, the largest database of such specimens available to date.

METHODS

Miyake-Apple posterior photographic technique.

MAIN OUTCOME MEASURES

The amount of decentration of rigid PC-IOLs and small-incision foldable PC-IOLs was analyzed, and the results were correlated with the type of fixation that had been achieved in each case.

RESULTS

Determination of mean values revealed that capsular bag fixation was achieved in 52.05% of eyes, asymmetric bag-sulcus fixation in 34.21 % of eyes, and sulcus-sulcus fixation in 13.74% of eyes. Asymmetrically fixed lenses consistently showed significant decentration. During the past 5 years (1993-98), the overall rate of in-the-bag fixation increased to 59.2%; by 1998 it had increased to 64%. Most significantly, success in achieving bag-bag fixation of foldable IOLs implanted in association with modern capsular surgery with small incisions has surged to 90% over the past 4 years.

CONCLUSIONS

The authors found a direct correlation of decentration in eyes with asymmetric fixation, and the results underscore the need for careful in-the-bag haptic placement. Although few surgeons today would dispute the goal to implanting haptics in the capsular bag, these findings show that the overall success rate over the years has, while improving, remained surprisingly low. The overall success rate of about 60% seen with all lens designs is probably as good as can be expected with classic large-incision extracapsular techniques. However, and most important and encouraging, the success rate of haptic fixation in cases with foldable lenses has improved dramatically during the past 4 years (up to the 90% range). This coincides with the present emphasis on modern capsular surgery and small-incision techniques used to insert these lenses.

[p16 gene suppresses growth of human esophageal carcinoma cells]

OBJECTIVE

To explore the effect of p16 gene on the growth inhibition of esophageal carcinoma cell line NEC.

METHODS

The full length of wild-type p16 cDNA was transfected into the esophageal carcinoma cell line of human fetus induced by N-methyl-N-benzylnitrosamine (NMBzA). In these esophageal carcinoma cell, p16 gene was homozygously deleted.

RESULTS

Expression of exogenous p16 gene in NEC cells was identified by dot blot and Western blot analyses. The growth rate of NEC transfected with p16 gene (NEC-p16) was markedly suppressed. Colony formation in soft agar was also decreased significantly. Cell cycle analysis by flow cytometry showed that the number of cells in G1-G0 phase of NEC-p16 cells was significantly increased while cells in S and G2 + M phase was decreased compared to that of the control NEC cells.

CONCLUSION

Transduction of wild type p16 gene into p16 gene-depleted esophageal cancer cells can restore its suppressive effect on cell growth by arrest of cell cycle at G1 phase.

[Synthetic assessment of health impact of cerebrovascular diseases on potential health days of life lost]

OBJECTIVE

To assess synthetically the impact on population health caused by cerebrovascular diseases.

METHODS

Incidence, duration of disease, disabilities and deaths of cerebrovascular diseases were analyzed with potential health days of life lost (PHDLL) as an indicator in urban areas of Changsha, Hunan Province.

RESULTS

The PHDLL caused by cerebrovascular disease totaled 2 624.94 days per thousand of population, 33.01% of them attributed to deaths and 53.44% to chronic disability.

CONCLUSION

Hemorrhagic cerebrovascular disease mainly lead to death and ischemic one caused chronic disability.