[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.

Pathological examination of an explanted phakic posterior chamber intraocular lens

PURPOSE

To report the clinicopathological correlation of an explanted phakic posterior chamber intraocular lens (PPC IOL) and to study the conformation of this lens implanted into human eyes obtained postmortem.

SETTING

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

METHODS

Three silicone PPC IOLs were explanted. One lens, explanted from a 38-year-old woman with complicated cataract, was submitted for pathological analysis. In addition to gross and scanning electron microscopy (SEM), the lens was studied after experimental implantation in human eyes obtained postmortem using frontal, posterior, and side-view techniques.

RESULTS

Although gross and SEM showed that the IOL was well polished, examination of the lens in human cadaver eyes showed it was oversized and poorly fixated. It was relatively bulky in its anterior-posterior dimension and revealed evidence of significant contact with the iris and crystalline lens.

CONCLUSIONS

This study illustrates many pitfalls to be avoided in the design of a plate PPC IOL. The lens in this report was too large, and instead of ciliary sulcus fixation, it showed poor fixation through the zonules onto the posterior face of the pars plicata. Present and future PPC IOLs should be submitted for similar preclinical studies to clarify the type and site of fixation.

Different apoptotic pathways are induced from various intracellular sites by tetraphenylporphyrins and light

The induction of apoptosis from different intracellular sites was studied by exposing V79 Chinese hamster fibroblasts to photodynamic therapy (PDT) with various porphyrins and light. The effects of two lipophilic, intracellular membrane-localized porphyrins, tetra(3-hydroxyphenyl)porphyrin (3THPP) and Photofrin, were compared with that of two sulphonated meso-tetraphenylporphines (TPPS2a and TPPS4), which are taken up into lysosomes by endocytosis. Apoptotic fractions induced by the various dyes and light were quantified by flow cytometry using the terminal deoxynucleotidyl transferase (TdT) assay. Cell fragmentation was measured in parallel, while the nuclear morphology of apoptotic cells was studied by fluorescence microscopy. Different kinetics were found for the induction of DNA strand breaks characteristic of apoptotic cells. PDT-induced damage to membranes resulted in an increasing number of apoptotic cells for about 12 h after PDT After damage to lysosomes, apoptotic cells were not detected until more than 12 h after PDT. Furthermore, apoptotic bodies were not observed after PDT-induced damage to intracellular membranes, whereas apoptosis induced from lysosomal sites was characterized by extensive cell fragmentation. Cell fragmentation occurred in combination with or in the absence of nuclear fragmentation. The results support the idea that the degradation phase of apoptosis can consist of a sequence of independent steps rather than a common final pathway.

Fructus corni attenuates oxidative stress in macrophages and endothelial cells

The antioxidant effect of a Chinese medicinal herb, Fructus corni extract (FCE), was investigated using models of oxidative stress in macrophages and vascular endothelial cells. Murine macrophages (J774) were incubated with FCE at 37 degrees C and 5% CO2 for 1 hr. Oxidative burst was triggered by zymosan and measured with a fluorescent probe. FCE exhibited a concentration- dependent suppression of oxidative burst. Confluent monolayers of bovine pulmonary artery endothelial cells (PAEC) were preincubated with FCE for 20 hrs, washed, and then exposed to an organic oxidant t-butyl hydroperoxide (tBHP) for 2 hrs. Cell viability was assessed by methylthiazol tetrazolium (MTT) assay, and cell injury by 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 tBHP resulted in decreased cell viability, increased LDH release, and elevated TBARS. Preincubation of PAEC with FCE significantly reversed these changes. Our results demonstrated that FCE can protect vascular endothelial cells from oxidant injury. The data thus suggest that Fructus corni may be useful for the prevention and/or treatment of disorders associated with oxidative damage.

Production of protoporphyrin IX induced by 5-aminolevulinic acid in transplanted human colon adenocarcinoma of nude mice can be increased by ultrasound

BALB/c nude mice bearing WiDr human colon adenocarcinoma were used to determine the effect of ultrasound on the production of 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) both in the tumors and in skin overlying the tumors. Ultrasound (1 MHz) with pulsed irradiation at an average intensity of 3 W/cm2 was given 10 min to the tumor area 10 min after administration of ALA (20% in an oil-in-water emulsion applied topically on the surface of the tumor for 30 min to 3 hr). An approximately 45% increase in the amount of PpIX produced by ALA in the tumors was obtained within 1 to 2 hr following ultrasound treatment. In particular, 1 hr after ultrasound treatment, the amount of PpIX in the tumors was at the same level as that 3 hr after ALA application alone. However, pulsed ultrasound irradiation for 5 min or continuous irradiation for 5 or 10 min had no significant effect on the production of PpIX by the tumor 1 hr after topical ALA application. Furthermore, in most cases, the amount of PpIX in the tumors was significantly decreased when ultrasound was given immediately before ALA application. There was no significant change in the ratio of the amount of PpIX in tumor to that in skin after ultrasound treatment. Most likely, the distribution of PpIX fluorescence in the tumors treated with ultrasound was more homogeneous than that in the tumors given ALA only. Our results provide a theoretical basis for possible clinical use of ultrasound-combined ALA or ALA based photodynamic therapy.

Susceptibility to esophageal cancer and genetic polymorphisms in glutathione S-transferases T1, P1, and M1 and cytochrome P450 2E1

Genetic polymorphisms in enzymes involved in carcinogen metabolism have been shown to influence susceptibility to cancer. Cytochrome P450 2E1 (CYP2E1) is primarily responsible for the bioactivation of many low molecular weight carcinogens, including certain nitrosamines, whereas glutathione S-transferases (GSTs) are involved in detoxifying many other carcinogenic electrophiles. Esophageal cancer, which is prevalent in China, is hypothesized to be related to environmental nitrosamine exposure. Thus, we conducted a pilot case-control study to examine the association between CYP2E1, GSTM1, GSTT1, and GSTP1 genetic polymorphisms and esophageal cancer susceptibility. DNA samples were isolated from surgically removed esophageal tissues or scraped esophageal epithelium from cases with cancer (n = 45), cases with severe epithelial hyperplasia (n = 45), and normal controls (n = 46) from a high-risk area, Linxian County, China. RFLPs in the CYP2E1 and the GSTP1 genes were determined by PCR amplification followed by digestion with RsaI or DraI and Alw26I, respectively. Deletion of the GSTM1 and GSTT1 genes was examined by a multiplex PCR. The CYP2E1 polymorphism detected by RsaI was significantly different between controls (56%) and cases with cancer (20%) or severe epithelial hyperplasia (17%; P < 0.001). Persons without the RsaI variant alleles had more than a 4-6-fold risk of developing severe epithelial hyperplasia (adjusted odds ratio, 6.0; 95% confidence interval, 2.3-16.0) and cancer (adjusted odds ratio, 4.8; 95% confidence interval, 1.8-12.4). Polymorphisms in the GSTs were not associated with increased esophageal cancer risk. These results indicate that CYP2E1 may be a genetic susceptibility factor involved in the early events leading to the development of esophageal cancer.

[FTIR study on the normal and tumor gastrointestinal tissues]

Series of cancer tissues and corresponding normal tissues of gastrointestinal tract (stomach, colon, esophagus) were studied by FTIR technique and the results showed the analogy of the spectra for the cancer tissues, while the spectra of normal tissues can be classified into three kinds. The secondary structures of protein were obtained by using deconvolution and curve-fitting techniques with Amide I bands and the results showed that the contents of alpha -helix and beta-sheet are different between the normal and cancer tissues.

Fructus corni enhances endothelial cell antioxidant defenses

1. The present study determined the effects of Fructus corni extract (FCE) on the levels of hydrogen peroxide (H2O2) and superoxide anion (O2-), on the glutathione (GSH) redox cycle and on the activities of antioxidant enzymes in bovine pulmonary artery endothelial cells (PAECs). 2. Confluent monolayers of PAECs were incubated with FCE, and oxidative stress was triggered by hypoxanthine and xanthine oxidase (to induce H2O2) or H2O2 (to induce O2-). 3. FCE exhibited a concentration-dependent suppression of H2O2 and O2-. 4. It modulated the GSH redox cycle by increasing the intracellular GSH content, the activities of GSH peroxidase and GSH disulfide reductase, and by decreasing the intracellular level of GSH disulfide. 5. It also increased the activities of superoxide dismutase and catalase. 6. These results demonstrate that FCE can promote a protective antioxidant defense state by affecting some important enzymatic and nonenzymatic oxidant-scavenging systems and may thus be useful for the prevention or treatment of disorders associated with oxidative damage.

Posterior capsular plaque: a common feature of cataract surgery in the developing world

PURPOSE

To study the histopathologic findings of posterior capsular plaque, a lesion that is discovered frequently in eyes undergoing cataract surgery in the developing world.

METHODS

Two hundred human crystalline lenses removed from 200 eyes of 200 patients who underwent intracapsular cataract extraction at Sagarmatha Choudhary Eye Hospital in Nepal were analyzed histopathologically.

RESULTS

Forty-nine lenses (24.5%) had a posterior capsular plaque. We confirm that the posterior plaques are composed of collagen that stains positively for Masson trichrome stain and that forms after pseudofibrous metaplasia of lens cells along the posterior capsule. The plaques form in a fashion analogous to a healing process.

CONCLUSIONS

We postulate that posterior capsular plaques result from posterior migration of epithelium and pseudofibrous metaplasia of lens epithelium. Most of the posterior capsular plaques are minute and not likely to affect vision. However, a small percentage of plaques are thicker and are likely to impair vision after extracapsular cataract surgery.

Mini-haptics to improve capsular fixation of plate-haptic silicone intraocular lenses

PURPOSE

To evaluate the effects of a new mini-haptic design on the strength and stability of capsular bag fixation of plate-haptic silicone intraocular lenses (IOLs) and determine whether this design encourages the growth of regenerating lens material or fibrous tissue around the haptic biomaterial and thus improves lens fixation in the capsular bag.

SETTING

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

METHODS

Six rabbits had bilateral continuous curvilinear capsulorhexis, phacoemulsification, and plate-haptic silicone IOL implantation. Each rabbit had a small-hole plate IOL (Chiron C10UB) implanted in the right eye and a mini-haptic plate IOL (Chiron C40UB) in the left eye. All rabbits were killed at 2 months. The force required to extract one haptic from the capsular bag was measured with a digital force gauge. Histopathologic analysis was performed on all specimens.

RESULTS

The mini-haptic style IOLs required significantly more extraction force than the small-hole design (P = .011). Histopathologically, proliferating lens epithelial cells were observed growing circumferentially around the mini-haptics, causing a 360 degree synechia formation. This formation did not occur with the conventional small-hole plate IOLs used as the control.

CONCLUSIONS

Lens epithelial cell proliferation around the mini-haptics significantly improved capsular bag fixation of the plate-haptic silicone IOL. This should decrease the incidence of clinical decentration and dislocation.

Fixation elements on plate intraocular lens: large positioning holes to improve security of capsular fixation

OBJECTIVE

This study aimed to evaluate in rabbit eyes the effects of large positioning holes in one-piece silicone plate-haptic intraocular lenses (IOLs) with respect to security of capsular bag fixation. Mechanical strength of capsular fixation is correlated with the histologic findings of regenerating lens material and fibrous tissue ingrowth through the positioning holes on silicone plate IOLs, comparing capsules implanted with large-hole style plate IOLs to fellow capsules implanted with small-hole style plate IOLs.

DESIGN

The study design was a prospective, randomized, experimental study.

PARTICIPANTS

A total of 40 fellow capsular bags from 20 New Zealand white rabbits were examined. Capsules implanted with conventional small-hole silicone plate IOLs were used as the control in all pairs of fellow capsules.

INTERVENTION

Phacoemulsification and implantation of a silicone plate IOL with small positioning holes in one eye and implantation of a silicone plate IOL with large positioning holes in the fellow eye were measured. All rabbits were killed at 2 months. The force required to extract the IOLs from the capsular bag was measured. All capsular bags underwent histopathologic analysis.

MAIN OUTCOME MEASURES

Extraction force measurements and histopathologic examination, comparing capsules implanted with small-hole plate IOLs with fellow capsules implanted with large-hole plate IOLs, were measured.

RESULTS

The large-hole style IOL required significantly more force to extract from the capsular bag compared to the conventional small-hole style (P = 0.003). Histologically, proliferating lens epithelial material and fibrous tissue were observed growing through all of the large positioning holes (synechia formation) but not through any of the small positioning holes.

CONCLUSIONS

Silicone plate IOLs with large positioning holes become affixed more firmly within the capsular bag compared to conventional small-hole plate IOLs. These findings suggest that large holes in silicone plate IOLs allow for superior capsular bag fixation. This should reduce the rates of decentration and dislocation.

[Use of 5-aminolevulinic acid in photochemotherapy and fluorescence diagnostics]

5-aminolevulinic acid is an early intermediate product in the synthesis of heme. Some of the enzymes in the heme synthesis chain have altered activities in tumor tissue, so that application of 5-aminolevulinic acid leads to an accumulation of protoporphyrin IX in tumors. This molecule absorbs light and acts as a potent photosensitizer; tumors containing the compound can therefore be destroyed by light. 5-aminolevulinic acid based photochemotherapy is presently being employed in the treatment of thin basal cell carcinomas in many countries. The cosmetic result of this treatment is excellent. Furthermore, it is a simple and inexpensive form of treatment with curative rates comparable to those of established therapy modalities. Experimentally, a number of other malignant lesions reachable by light via optical fibers are being treated. Since protoporphyrin IX has a characteristic red fluorescence, 5-aminolevulinic acid can also be applied for diagnostic purposes.

Apoptosis induction by different pathways with methylene blue derivative and light from mitochondrial sites in V79 cells

The importance of mitochondria for the induction of apoptosis by photodynamic therapy (PDT) was studied with a new photosensitizing dye, methylene blue derivative (MBD), and light. By using fluorescence microscopy and by measuring the MBD-PDT-induced inhibition of specifically subcellularly localized marker enzymes, we show that MBD is localized in mitochondria and not in lysosomes, endoplasmic reticulum or Golgi apparatus of V79 Chinese hamster fibroblasts. Cellular uptake kinetics and fluorescence properties of the dye in cells were characterized. Cell death was studied by a cell survival assay and by flow cytometry of cells stained using the terminal deoxynucleotidyl transferase (TdT) assay. MBD with light induced cell death by apoptosis via 2 different pathways, one rapid and one delayed, depending on the amount of dye in the cells. Cells treated with an MBD concentration higher than 0.05 microg/ml died by apoptosis within 3 hr after light exposure. At a concentration of 0.05 microg/ml MBD, cell death was induced slowly, and apoptotic cells appeared increasingly from the second day after PDT. Combination studies with 2-deoxyglucose (2-DOG) and carbonylcyanide-m-chlorophenylhydrazone (CCCP), inhibitors of glycolysis and oxidative phosphorylation, respectively, indicated that MBD and light inhibited mitochondrial oxidative phosphorylation. Abolishment of both energy sources led to cell death by necrosis within 6 hr. Inhibition of glycolysis alone induced apoptosis between 3 and 6 hr, while inhibition of mitochondrial oxidative phosphorylation alone led to delayed apoptosis within days.

[Genetic polymorphisms of cytochrome P450 2E1 and glutathione S-transferase P1 and susceptibility to esophageal cancer]

OBJECTIVES

To study the association between genetic polymorphisms of cytochrome P4502E1 (CYP2E1) and/or glutathione S-transferase P1 (GSTP1) and susceptibility to esophageal cancer.

METHODS

Genotyping of CYP2E1 and GSTP1 was performed using PCR-based RFLP analysis on DNA isolated from surgically removed esophageal tissues or scraped esophageal epithelium from cancer cases (n = 45), severe epithelial hyperplasia cases (n = 45), and normal controls (n = 45).

RESULTS

The variant genotypes (c1/c2 and c2/c2) detected by RsaI digestion was found in 17% of epithelial hyperplasia cases, 20.0% of esophageal cancer cases and 55.6% of controls, with the differences being statistically significant (P < 0.001). Subjects carrying wild-type genotype of CYP2E1 had more than 5-fold risk for developing severe epithelial hyperplasia (odds ratio, OR = 5.78; 95% confidence interval, CI = 2.2-15.2) and esophageal cancer (OR = 5.00; 95% CI = 2.0-12.8). No association with the risk of severe epithelial hyperplasia and esophageal cancer was observed for the DraI polymorphism of CYP2E1 or for the Awl26I polymorphism of GSTP1.

CONCLUSION

CYP2E1 is a genetic susceptibility factor involved in the early events for esophageal carcinogenesis.

[Deletion of MTS1/p16 gene in human esophageal carcinoma]

OBJECTIVE

To investigate the alteration of MTS1/p16 gene in human esophageal carcinoma.

METHODS

A total of 60 human esophageal tissue specimens, comprising 30 squamous-cell carcinomas and 30 tumor-adjacent tissue specimens, were examined for homozygous deletion of p16 gene by using Southern blot hybridization and PCR method.

RESULTS

The results showed that no deletions were detected in 30 tumor-adjacent tissue samples. However, of 30 esophageal carcinoma specimens, 7 were found negative for p16 gene in Southern blot assay, and the deletion of the p16 gene in 5 samples were confirmed by PCR with a 16.7% p16 gene deletion rate.

CONCLUSION

These data suggest that MTS1/p16 gene alterations may play a role in the progression of human esophageal carcinoma.

Potent induction of a neutrophil and eosinophil-rich infiltrate in vivo by human mast cell tryptase: selective enhancement of eosinophil recruitment by histamine

Tryptase is the most abundant protein constituent of the secretory granules of human mast cells, but little is known of the contribution of this serine proteinase in acute allergic reactions. We have purified tryptase from human lung tissue by immunoaffinity procedures, and have investigated its potential to provoke an inflammatory infiltrate in vivo. Within 6 h of injection into the skin of guinea pigs, the accumulation of large numbers of neutrophils and eosinophils was observed, and those eosinophils closest to the injection site were partially degranulated. Similarly, injection of tryptase into the peritoneum of mice, even in quantities as low as 5 ng, stimulated the ingress of neutrophils. The response was dose dependent at 3, 6, and 16 h, with increases in median numbers of up to 400-fold. At the later time points eosinophil numbers were increased by up to 10-fold, and there were elevations also in the numbers of lymphocytes and macrophages. In both models, the actions of tryptase appeared to be dependent on an intact catalytic site. Coinjection of heparin with tryptase had relatively little effect on tryptase-induced responses. On the other hand, although histamine did not itself stimulate cell accumulation, over a range of concentrations it altered the cellular composition of the infiltrate induced by tryptase. Addition of histamine to tryptase provoked selective increases in eosinophil numbers of up to fivefold in the mouse peritoneum. Tryptase may provide an important stimulus for granulocyte recruitment in allergic disease.

Potent induction of a neutrophil and eosinophil-rich infiltrate in vivo by human mast cell tryptase: selective enhancement of eosinophil recruitment by histamine

Tryptase is the most abundant protein constituent of the secretory granules of human mast cells, but little is known of the contribution of this serine proteinase in acute allergic reactions. We have purified tryptase from human lung tissue by immunoaffinity procedures, and have investigated its potential to provoke an inflammatory infiltrate in vivo. Within 6 h of injection into the skin of guinea pigs, the accumulation of large numbers of neutrophils and eosinophils was observed, and those eosinophils closest to the injection site were partially degranulated. Similarly, injection of tryptase into the peritoneum of mice, even in quantities as low as 5 ng, stimulated the ingress of neutrophils. The response was dose dependent at 3, 6, and 16 h, with increases in median numbers of up to 400-fold. At the later time points eosinophil numbers were increased by up to 10-fold, and there were elevations also in the numbers of lymphocytes and macrophages. In both models, the actions of tryptase appeared to be dependent on an intact catalytic site. Coinjection of heparin with tryptase had relatively little effect on tryptase-induced responses. On the other hand, although histamine did not itself stimulate cell accumulation, over a range of concentrations it altered the cellular composition of the infiltrate induced by tryptase. Addition of histamine to tryptase provoked selective increases in eosinophil numbers of up to fivefold in the mouse peritoneum. Tryptase may provide an important stimulus for granulocyte recruitment in allergic disease.

[Penetration of ciprofloxacin and cefoperazone into human pancreas]

Major pancreatic infection is responsible for more than 80% of deaths in patients with acute pancreatitis. Therefore, the role of antimicrobial drugs in the prevention and treatment of secondary parcreatic infection is very important. The choice of antimicrobial drugs must be based upon the ability of the drug to exceed the therapeutic concentration in pancreas for the common pathogens. The penetration of ciprofloxacin and cefoperazone into pancreas was investigated in ten patients who had undergone pancreatoduodenectomy. The pancreatic juice was temporarily diverted to the exterior via a panoreatic duct catheter. The pancreatic tissue was obtained intraoperatively and pancreatic juice was drained postoperatively. The antimicrobial drug concentrations were determined by high-performance liquid chromatography. The concentrations of ciprofloxacin and cefoperazone in pancreatic juice were 44% and 17%, respectively, of those in serum, and exceeded the in vitro concentration (MIC-90) for most bacteria associated with pancreatic infections. The result indicates that ciprofloxacin and cefoprazone appear to be appropriate for both prophylaxis and therapy of secondary pancreatic infections.

Security of capsular fixation: small-versus large-hole plate-hepatic lenses

PURPOSE

To assess the effect of relatively large positioning holes on the security of capsular bag fixation of plate-haptic silicone intraocular lenses (IOLs).

SETTING

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

METHODS

This study tested the hypothesis that larger holes allow ingrowth of lens material, fibrous tissue, or both through them, which helps fixate the lens more firmly in the capsular bag. Five rabbits had bilateral continuous curvilinear capsulorhexis, phacoemulsification, and implantation of a plate-haptic silicone IOL. An IOL with a small, round positioning hole (Staar AA-4203V) was implanted in the right eye in each rabbit, and a large-hole IOL (Staar AA-4203VF) was implanted in the left eye. After 2 months, all rabbits were killed. The force required to extract one haptic from the capsular bag was measured with a digital force meter. All eyes had histopathological analysis.

RESULTS

It was slightly more difficult to extract a large-hole IOL from the capsular bag, although this trend was not statistically significant. However, histopathological analysis consistently showed 360 degree synechia formation through the holes, showing that the IOL could be securely fixed in position.

CONCLUSIONS

Proliferation of lens epithelial cells through a large positioning hole in a plate-haptic silicone IOL may improve the long-term security of capsular bag fixation. This will help reduce the incidence of IOL decentration and dislocation.

[Studies on expansion ex vivo of murine bone marrow cells and its hematopoietic reconstitution capacity]

OBJECTIVE

To investigate the effects of stem cell factor (SCF) in combination with interleukin-1 (IL-1) or/and interleukin-3 (IL-3) on ex vivo expansion of 5FU treated bone marrow cells and hematopoietic recovery in lethally irradiated mice transplanted with the expanded cells.

METHODS

5FU treated bone marrow cells (d3-5FU-BMC) were cultured in a cytokines-containing medium, and the net increments of CFU-GM and high proliferative potential colony forming cell (HPP-CFC) were evaluated.

RESULTS

CFU-GM increased by 33.7 +/- 18.1- or 18.1 +/- 6.3- fold, and HPP-CFC by 17.8 +/- 10.5- or 12.7 +/- 9.1- fold, respectively, in cultures containing SCF with IL- or IL-3, as compared with that in control; while SCF alone had little effect. Compared with fresh d3-5FU-BMC, transplantation of the expanded bone marrow cells accelerated the recovery of recipients' peripheral blood cell counts by 1 approximately 3 days and increased the survival rate of the transplanted animals (d3-5FU-BMC group 50% vs expansion group 8U approximately 100%).

CONCLUSION

SCF in combination with IL-1 or IL-3 synergetically ex vivo expands hematopoietic cells. Transplantation of the expanded bone marrow cells accelerates the recipient's hematopoietic reconstitution.

5-Aminolevulinic acid-based photodynamic therapy. Clinical research and future challenges

BACKGROUND

Photodynamic therapy (PDT) for cancer patients has developed into an important new clinical treatment modality in the past 25-years. PDT involves administration of a tumor-localizing photosensitizer or photosensitizer prodrug (5-aminolevulinic acid [ALA], a precursor in the heme biosynthetic pathway) and the subsequent activation of the photosensitizer by light. Although several photosensitizers other than ALA-derived protoprophyrin IX (PpIX) have been used in clinical PDT, ALA-based PDT has been the most active area of clinical PDT research during the past 5 years. Studies have shown that a higher accumulation of ALA-derived PpIX in rapidly proliferating cells may provide a biologic rationale for clinical use of ALA-based PDT and diagnosis. However, no review updating the clinical data has appeared so far.

METHODS

A review of recently published data on clinical ALA-based PDT and diagnosis was conducted.

RESULTS

Several individual studies in which patients with primary nonmelanoma cutaneous tumors received topical ALA-based PDT have reported promising results, including outstanding cosmetic results. However, the modality with present protocols does not in general, appear to be superior to conventional therapies with respect to initial complete response rates and long term recurrence rates, particularly in the treatment of nodular skin tumors. Topical ALA-PDT does have the following advantages over conventional treatments: it is noninvasive; it produces excellent cosmetic results; it is well tolerated by patients; it can be used to treat multiple superficial lesions in short treatment sessions; it can be applied to patients who refuse surgery or have pacemakers and bleeding tendency; it can be used to treat lesions in specific locations, such as the oral mucosa or the genital area; it can be used as a palliative treatment; and it can be applied repeatedly without cumulative toxicity. Topical ALA-PDT also has potential as a treatment for nonneoplastic skin diseases. Systemic administration of ALA does not seem to be severely toxic, but the advantage of using this approach for PDT of superficial lesions of internal hollow organs is still uncertain. The ALA-derived porphyrin fluorescence technique would be useful in the diagnosis of superficial lesions of internal hollow organs.

CONCLUSIONS

Promising results of ALA-based clinical PDT and diagnosis have been obtained. The modality has advantages over conventional treatments. However, some improvements need to be made, such as optimization of parameters of ALA-based PDT and diagnosis; increased tumor selectivity of ALA-derived PpIX; better understanding of light distribution in tissue: improvement of light dosimetry procedure; and development of simpler, cheaper, and more efficient light delivery systems.

5-Aminolevulinic acid-based photodynamic therapy. Clinical research and future challenges

BACKGROUND

Photodynamic therapy (PDT) for cancer patients has developed into an important new clinical treatment modality in the past 25-years. PDT involves administration of a tumor-localizing photosensitizer or photosensitizer prodrug (5-aminolevulinic acid [ALA], a precursor in the heme biosynthetic pathway) and the subsequent activation of the photosensitizer by light. Although several photosensitizers other than ALA-derived protoprophyrin IX (PpIX) have been used in clinical PDT, ALA-based PDT has been the most active area of clinical PDT research during the past 5 years. Studies have shown that a higher accumulation of ALA-derived PpIX in rapidly proliferating cells may provide a biologic rationale for clinical use of ALA-based PDT and diagnosis. However, no review updating the clinical data has appeared so far.

METHODS

A review of recently published data on clinical ALA-based PDT and diagnosis was conducted.

RESULTS

Several individual studies in which patients with primary nonmelanoma cutaneous tumors received topical ALA-based PDT have reported promising results, including outstanding cosmetic results. However, the modality with present protocols does not in general, appear to be superior to conventional therapies with respect to initial complete response rates and long term recurrence rates, particularly in the treatment of nodular skin tumors. Topical ALA-PDT does have the following advantages over conventional treatments: it is noninvasive; it produces excellent cosmetic results; it is well tolerated by patients; it can be used to treat multiple superficial lesions in short treatment sessions; it can be applied to patients who refuse surgery or have pacemakers and bleeding tendency; it can be used to treat lesions in specific locations, such as the oral mucosa or the genital area; it can be used as a palliative treatment; and it can be applied repeatedly without cumulative toxicity. Topical ALA-PDT also has potential as a treatment for nonneoplastic skin diseases. Systemic administration of ALA does not seem to be severely toxic, but the advantage of using this approach for PDT of superficial lesions of internal hollow organs is still uncertain. The ALA-derived porphyrin fluorescence technique would be useful in the diagnosis of superficial lesions of internal hollow organs.

CONCLUSIONS

Promising results of ALA-based clinical PDT and diagnosis have been obtained. The modality has advantages over conventional treatments. However, some improvements need to be made, such as optimization of parameters of ALA-based PDT and diagnosis; increased tumor selectivity of ALA-derived PpIX; better understanding of light distribution in tissue: improvement of light dosimetry procedure; and development of simpler, cheaper, and more efficient light delivery systems.

5-Aminolevulinic acid-based photodynamic therapy. Clinical research and future challenges

BACKGROUND

Photodynamic therapy (PDT) for cancer patients has developed into an important new clinical treatment modality in the past 25-years. PDT involves administration of a tumor-localizing photosensitizer or photosensitizer prodrug (5-aminolevulinic acid [ALA], a precursor in the heme biosynthetic pathway) and the subsequent activation of the photosensitizer by light. Although several photosensitizers other than ALA-derived protoprophyrin IX (PpIX) have been used in clinical PDT, ALA-based PDT has been the most active area of clinical PDT research during the past 5 years. Studies have shown that a higher accumulation of ALA-derived PpIX in rapidly proliferating cells may provide a biologic rationale for clinical use of ALA-based PDT and diagnosis. However, no review updating the clinical data has appeared so far.

METHODS

A review of recently published data on clinical ALA-based PDT and diagnosis was conducted.

RESULTS

Several individual studies in which patients with primary nonmelanoma cutaneous tumors received topical ALA-based PDT have reported promising results, including outstanding cosmetic results. However, the modality with present protocols does not in general, appear to be superior to conventional therapies with respect to initial complete response rates and long term recurrence rates, particularly in the treatment of nodular skin tumors. Topical ALA-PDT does have the following advantages over conventional treatments: it is noninvasive; it produces excellent cosmetic results; it is well tolerated by patients; it can be used to treat multiple superficial lesions in short treatment sessions; it can be applied to patients who refuse surgery or have pacemakers and bleeding tendency; it can be used to treat lesions in specific locations, such as the oral mucosa or the genital area; it can be used as a palliative treatment; and it can be applied repeatedly without cumulative toxicity. Topical ALA-PDT also has potential as a treatment for nonneoplastic skin diseases. Systemic administration of ALA does not seem to be severely toxic, but the advantage of using this approach for PDT of superficial lesions of internal hollow organs is still uncertain. The ALA-derived porphyrin fluorescence technique would be useful in the diagnosis of superficial lesions of internal hollow organs.

CONCLUSIONS

Promising results of ALA-based clinical PDT and diagnosis have been obtained. The modality has advantages over conventional treatments. However, some improvements need to be made, such as optimization of parameters of ALA-based PDT and diagnosis; increased tumor selectivity of ALA-derived PpIX; better understanding of light distribution in tissue: improvement of light dosimetry procedure; and development of simpler, cheaper, and more efficient light delivery systems.

Silicone oil adhesion to intraocular lenses: an experimental study comparing various biomaterials

PURPOSE

To perform an in vitro experimental study comparing the degree of adherence of silicone oil to various rigid and foldable intraocular lens (IOL) designs and to the human lens capsule.

SETTING

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

METHODS

Seven IOL styles comprising various biomaterials were studied: fluorine-treated (Fluorlens), heparin-surface-modified (HSM), hydrogel, Memory-Lens, Poly(methyl methacrylate) (PMMA), soft acrylic, and silicone lenses; the human crystalline lens was also studied. Each lens was immersed in silicone oil for 12 hours, than photographed, studied by scanning electron microscopy (except the crystalline lens), and subjected to computer-generated image analysis to determine the silicone oil coverage.

RESULTS

Silicone oil coverage of dry silicone lenses was 100% and of lenses immersed in normal saline, 82.5%. The least coverage was on the heparin-surface-modified lens (mean score 9.4%). Coverage of the other four lenses ranged from approximately 15.1% to 33.7%. Mean coverage of the human lens capsule was 10.9%.

CONCLUSION

Although a silicone IOL shows maximal adherence to silicone oil, other lens biomaterials are not immune to this complication. Silicone oil coverage was related to the dispersive energy component of the surface charge of the IOL biomaterial. Low dispersive energy materials had less silicone oil coverage, while those with higher dispersive energy had more oil coverage.