Iron status and cardiovascular risk factors in patients with haemodialysis versus patients with ischaemic heart disease

AIM

The study aimed to investigate whether imbalanced iron status in patients with haemodialysis coexisted with abnormal lipid profile, higher inflammatory status and altered growth hormone-insulin-like growth factor (GH-IGF)-I axis and to compare these biochemical markers with patients with ischaemic heart disease.

METHODS

Serum samples for biochemical and immunological analyses were collected from 74 normal subjects, 138 patients with ischaemic heart disease (IHD) and 115 patients on haemodialysis (HD).

RESULTS

Compared with normal subjects, lower serum iron, lower total iron-binding capacity (TIBC) and higher ferritin in HD patients coexisted with decreases in high-density lipoprotein cholesterol and total bilirubin as well as increases in lactate dehydrogenase (LDH), interleukin (IL)-6, C-reactive protein (CRP) and IL-10. Decreased IGF-I and increased GH were found in HD patients whereas unchanged GH-IGF axis were found in IHD patients. Compared with IHD, much higher ferritin, lower TIBC, lower bilirubin and higher LDH levels were found in HD patients.

CONCLUSION

Imbalanced iron status in patients on HD coexisted with abnormal lipid profiles, increased anaerobic activity and higher inflammatory status, which suggests that imbalanced iron status in HD patients may play a deleterious role in cardiovascular pathophysiology. Altered GH-IGF axis found in HD patients was more obvious than in IHD patients. This may imply that the GH-IGF axis system is modulated or adapted by HD.

Cardiac Fas-dependent and mitochondria-dependent apoptosis in ovariectomized rats

BACKGROUND

Very limited information has been published regarding cardiac apoptosis in menopausal women or in those after bilateral oophorectomy. The purpose of this study was to evaluate whether cardiac Fas-dependent (type I) and mitochondria-dependent (type II) apoptotic pathways are activated in ovariectomized rats.

METHODS

Thirty-two female Wistar rats at 6-7 months of age were randomly divided into sham-operated group (Sham) and bilateral ovariectomized group (OVX). Two months after the operation, the cardiac characteristics, myocardial architecture, and two major apoptotic pathways in the excised left ventricle from rats were measured by histopathological analysis, Western blotting and reverse transcription polymerase chain reaction (RT-PCR), and positive TUNEL assays.

RESULTS

The whole heart weight, the left ventricular weight, the ratios of whole heart weight to tibia length, and the ratios of left ventricle to tibia length were significantly increased in OVX relative to Sham. Abnormal myocardial architecture, enlarged interstitial spaces, more minor cardiac fibrosis, and more cardiac TUNEL-positive apoptotic cells were observed in OVX. The key components of Fas-dependent apoptosis (TNF-alpha, Fas ligand, Fas death receptors, Fas-associated death domain (FADD), activated caspase 8, and activated caspase 3) and key components of mitochondria-dependent apoptosis (Bad, Bax, Bax-to-Bcl2 ratio, cytosolic cytochrome c, activated caspase 9, and activated caspase 3) were significantly increased in OVX hearts.

CONCLUSIONS

The absence of female ovaries will activate the cardiac Fas-dependent and mitochondria-dependent apoptotic pathways, which might provide one of possible mechanism for developing heart failure in post-menopause women.

p38 mitogen-activated protein kinase pathway is involved in protein kinase Calpha-regulated invasion in human hepatocellular carcinoma cells

Protein kinase Calpha (PKCalpha) has been suggested to play an important role in tumorigenesis, invasion, and metastasis. In this study, we investigated the signal pathways selectively activated by PKCalpha in human hepatocellular carcinoma (HCC) cells to determine the role of mitogen-activated protein kinases (MAPK) in PKCalpha-mediated HCC migration and invasion. A stable SK-Hep-1 cell clone (siPKCalpha-SK) expressing DNA-based small interfering RNA (siRNA) PKCalpha was established and was then characterized by cell growth, migration, and invasion. The expression of PKCalpha was decreased in siPKCalpha-SK, and cell growth, migration, and invasion were reduced. These changes were associated with the decrease in p38 MAPK phosphorylation level, but not in c-jun-NH(2)-kinase-1/2 (JNK-1/2) and extracellular signal-regulated kinase-1/2 (ERK-1/2). This phenomenon was confirmed in the SK-Hep-1 cells treated with antisense PKCalpha olignucleotide. The p38 MAPK inhibitor SB203580 or dominant negative p38 mutant plasmid (DN-p38) was used to evaluate the dependency of p38 MAPK in PKCalpha-regulated migration and invasion. Attenuation of cell migration and invasion was revealed in the SK-Hep-1 cells treated with the SB203580 or DN-p38, but not with ERK-1/2 inhibitor PD98059 or JNK-1/2 inhibitor SP600125. Overexpression of constitutively active MKK6 or PKCalpha may restore the inactivation of p38 and the attenuation of cell migration and invasion in siPKCalpha-SK. Similar findings were observed in the stable HA22T/VGH cell clone expressing siRNA PKCalpha. This study provides new insight into the role of p38 MAPK in PKCalpha-mediated malignant phenotypes, especially in PKCalpha-mediated cancer cell invasion, which may have valuable implications for developing new therapies for some PKCalpha-overexpressing cancers.

Measurement of ocular torsion using iterative optical flow

This work represents a new method for measuring ocular torsion using optical flow. Feature points are obtained from reference and current image, and the relative optical flows of each point are calculated. The feature points are selected according to the strength of corner on the signature of iris. This method is robust and effective in calculation.

Porphyromonas gingivalis-induced cellular hypertrophy and MMP-9 activity via different signaling pathways in H9c2 cardiomyoblast cells

BACKGROUND

Little is known about the pathogenesis of cardiomyocyte hypertrophy caused by periodontitis pathogens. The purpose of this study was to determine the effect of the periodontal pathogen Porphyromonas gingivalis on cardiomyocyte hypertrophy.

METHODS

Matrix metalloproteinase (MMP)-2 and MMP-9 activities and cellular morphology were measured by gelatin zymography and immunofluorescence after P. gingivalis-medium treatment with or without SB203580 (p38 mitogen-activated protein kinase cascade [p38] inhibitor), U0126 (mitogen-activated protein kinase kinase [MAPKK] inhibitor), LY294002 (phosphoinositide 3-kinase [PI3K] inhibitor), cyclosporin A (CsA; calcineurin inhibitor), SP600125 (c-Jun N-terminal kinase [JNK] inhibitor), proinflammatory interleukin (IL)-1, or anti-inflammatory IL-10 in cultured cardiomyoblast H9c2 cells.

RESULTS

P. gingivalis medium increased MMP-9 activities and cellular sizes (+87%) of H9c2 cells, whereas Actinobacillus actinomycetemcomitans medium and Prevotella intermedia medium had no effects. The increased activity of MMP-9 treated with P. gingivalis medium was not mediated through p38, extracellular-regulated kinase (ERK), PI3K, calcineurin, and JNK signaling pathways and was not inhibited by IL-10. However, the hypertrophy of H9c2 cells induced with P. gingivalis medium was reduced by administration of SB203580 (-37%), U0126 (-35%), LY294002 (-49%), CsA (-49%), and SP600125 (-24%).

CONCLUSIONS

Our findings suggest that P. gingivalis medium elevated MMP-9 activity and induced cardiomyoblast hypertrophy. However, P. gingivalis-induced H9c2 cell hypertrophy was mediated through p38, ERK, PI3K, calcineurin, and JNK signaling pathways, which are in a totally different regulatory pathway from P. gingivalis-elevated MMP-9 activity. These findings provide evidence that P. gingivalis infection activated multiple factors via different pathways to induce the development of hypertrophy of H9c2 cardiomyoblast cells.

Porphyromonas gingivalis-related cardiac cell apoptosis was majorly co-activated by p38 and extracellular signal-regulated kinase pathways

BACKGROUND AND OBJECTIVE

Little is known about the pathogenesis of apoptosis caused in cardiac tissues by periodontitis pathogens. The purpose of this study was to determine the related effect of periodontal pathogen Porphyromonas gingivalis on cardiac cell apoptosis.

METHODS

DNA fragmentation, nuclear condensation and activated apoptotic caspases were measured by agarose gel electrophoresis, nuclear DAPI (4',6-diamidine-2-phenylindole dihydrochloride) stain and western blotting analysis following the surrounding medium of P. gingivalis and/or pre-administration of SB203580 (p38 inhibitor), U0126 [mitogen-activated protein kinase (MAPK) extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor], LY294002 [phosphoinositide 3-kinase (PI3K) inhibitor], cyclosporine A (CsA: calcineurin inhibitor), and Sp600125 [c-Jun N-terminal kinase (JNK) inhibitor] in cultured cardiac H9c2 cells.

RESULTS

The surrounding medium of periodontal pathogen P. gingivalis increased DNA fragmentation, nuclear condensation and the activated apoptotic caspase-3, -8, and -9 proteins in H9c2 cells. DNA fragmentation and nuclear condensation of H9c2 cells treated with P. gingivalis medium were completely blocked by SB203580 plus U0126 and were decreased after pre-administration of SB203580 only, U0126 only, LY294002, CsA, but were increased by Sp600125.

CONCLUSION

Our findings suggest that the development of cardiac cell apoptosis can be directly induced by P. gingivalis medium. Porphyromonas gingivalis-related H9c2 cell apoptosis was mainly co-activated by p38 and ERK pathways and may be involved in death receptor-dependent (caspase 8) and mitochondria (caspase 9)-dependent apoptotic pathways. Porphyromonas gingivalis-related cardiac cell apoptosis was also partially mediated by PI3K or calcineurin signaling pathways, whereas the JNK pathway might play a protective role in P. gingivalis-related cardiac cell apoptosis.

Second-hand smoke-induced cardiac fibrosis is related to the Fas death receptor apoptotic pathway without mitochondria-dependent pathway involvement in rats

Exposure to environmental tobacco smoke has been epidemiologically linked to heart disease among nonsmokers. However, the molecular mechanism behind the pathogenesis of cardiac disease is unknown. In this study, we found that Wistar rats, exposed to tobacco cigarette smoke at doses of 5, 10, or 15 cigarettes for 30 min twice a day for 1 month, had a dose-dependently reduced heart weight to body weight ratio and enhanced interstitial fibrosis as identified by histopathologic analysis. The mRNA and activity of matrix metalloprotease-2 (MMP-2), representing the progress of cardiac remodeling, were also elevated in the heart. In addition, we used reverse-transcriptase polymerase chain reaction and Western blotting to demonstrate significantly increased levels of the apoptotic effecter caspase-3 in treated animal hearts. Dose-dependently elevated mRNA and protein levels of Fas, and promoted apoptotic initiator caspase-8 (active form), a molecule of a death-receptor-dependent pathway, coupled with unaltered or decreased levels of cytosolic cytochrome c and the apoptotic initiator caspase-9 (active form), molecules of mitochondria-dependent pathways, may be indicative of cardiac apoptosis, which is Fas death-receptor apoptotic-signaling dependent, but not mitochondria pathway dependent in rats exposed to second-hand smoke (SHS). With regard to the regulation of survival pathway, using dot blotting, we found cardiac insulin-like growth factor-1 (IGF-1) and IGF-1 receptor mRNA levels to be significantly increased, indicating that compensative effects of IGF-1 survival signaling could occur. In conclusion, we found that the effects of SHS on cardiomyocyte are mediated by the Fas death-receptor-dependent apoptotic pathway and might be related to the epidemiologic incidence of cardiac disease of SHS-exposed nonsmokers.

17beta-estradiol reduces cardiac hypertrophy mediated through the up-regulation of PI3K/Akt and the suppression of calcineurin/NF-AT3 signaling pathways in rats

This study was designed to determine the effects of 17beta-estradiol (E2) in overcoming the cardiac over-loading and cardiac fibrosis in rats. E2 (100 ng/kg) or oil was applied in female Sprague-Dawley rats with or without bilateral ovariectomy and with or without coarctation of the abdominal aorta after 4 or 8 days. By post-operative day 4, the heart weight, the left ventricular weight, the latent form of MMP-2 in rat hearts with or without the ovary intact had significantly increased while these changes were reversed after E2 treatment. Although animals with the ovaries intact overcame the hypertrophic effects and the consumption of MMP-2, these effects were not restored in ovariectomized animals in which more fibrosis could be found by day 8. Among the IGF-I signaling, the levels of IGF-I, the activities of PI3K-Akt for cardiomyocyte survival, and MEK-ERKs for non-cardiomyocyte proliferation pathways had significantly increased by day 4. These increasing trends were enhanced by E2 treatment. However, down-regulation was only observed on day 8 in ovariectomized animals. Similarly, elevated expressions of the steady-state mRNA of IGF-I, IGF-IR, and Cox vb were observed on day 4 in animals with the ovaries intact and these expressions were enhanced by E2 treatment. In contrast, down-regulation on day 8 in ovariectomized animals was not enhanced by E2. The calcineurin/NFAT-3 pathway was suppressed on day 4 but was elevated on day 8 in ovariectomized animals. These findings indicate that signaling pathways may be plausible mechanisms for the cardiac protective effects of E2 administration.

Protective effects of baicalein on tert-butyl hydroperoxide-induced hepatic toxicity in rat hepatocytes

Baicalein (BAL), a main flavonoid constituent of Scutellaria radix, was studied for its inhibitory effects on tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity and oxidative damage in primary cultures of rat hepatocytes. In a preliminary study, baicalein revealed effective antioxidant properties in a test of its capacity to quench the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH). Further investigations showed that baicalein, at the concentrations of 1, 5, and 10 microM, decreased the leakage of lactate dehydrogenase (LDH) and alanine aminotransferase (ALT) and the formation of malondialdehyde (MDA) induced by 30 min of pretreatment with t-BHP (1.5 mM) in primary cultures of rat hepatocytes. Baicalein also attenuated t-BHP-induced mitochondrial depolarization as determined by a retention test of rhodamine 123 and DNA repair synthesis as evidenced by unscheduled DNA synthesis (UDS). In addition, baicalein decreased the 8-hydroxy-2'-deoxyguanosine (8-OH-dG) content which acts as a DNA damage marker. The sum of the results suggests that the protective effect of baicalein against the cytotoxicity and genotoxicity of hepatocytes induced by t-BHP is due to its ability to quench free radicals.

Protective effect of baicalin on tert-butyl hydroperoxide-induced rat hepatotoxicity

Baicalin (BA) is a flavonoid compound purified from Scutellaria baicalensis Georgi that is used as a traditional Chinese herbal medicine. Baicalin was studied for the mechanism of its inhibitory effects on the tert-butyl hydroperoxide (t-BHP)-induced cytotoxicity and lipid peroxidation in rat liver system. Baicalin expressed an antioxidant property by its capacity for quenching the free radicals of 1,1-diphenyl-2-picrylhydrazyl (DPPH). Further investigations using the t-BHP-induced cytotoxicity in rat primary hepatocytes demonstrated that baicalin, at the concentrations of 2-220 microM, significantly decreased the leakages of lactate dehydrogenase (LDH) and alanine aminotransferase (ALT), and the formation of malondialdehyde (MDA) induced by 30 min treatment of t-BHP(1.5 mM). Baicalin also attenuated the t-BHP-induced depletion of glutathione (GSH) and high level of DNA repaired synthesis. An in vivo study in rats showed that pretreatment with baicalin (i.p.) at concentrations of 0.5 and 5 mg/kg for 5 days before a single i.p. dose of t-BHP (0.1 mmol/kg) significantly lowered the serum levels of hepatic enzyme markers (ALT and AST) and reduced oxidative stress in the liver. Histopathological evaluation of the rat livers revealed that baicalin reduced the incidence of liver lesions induced by t-BHP including hepatocyte swelling, leukocyte infiltration, and necrosis. Based on the results described above, we speculate that baicalin may play a chemopreventive role via reducing oxidative stress in living systems.

Inhibitory effect of berberine on tert-butyl hydroperoxide-induced oxidative damage in rat liver

Berberine, a main protoberberine component of Coptidis Rhizoma, was studied for the mechanism of its inhibitory effects on the tert-butyl hydroperoxide (t-BHP)-induced cytotoxicity and lipid peroxidation in rat liver. In the preliminary study, berberine expressed an antioxidant property by its capacity for quenching the free radicals of 1,1-diphenyl-2-picrylhydrazyl (DPPH). Further investigations were conducted using t-BHP-induced cytotoxicity in rat primary hepatocytes and hepatotoxicity in rats to evaluate the antioxidative bioactivity of berberine. The results in rat primary hepatocytes demonstrated that berberine, at the concentrations of 0.01-1.0 mM, significantly decreased the leakage of lactate dehydrogenase (LDH) and alanine aminotransferase (ALT), and the formation of malondialdehyde (MDA) induced by 30 min treatment of t-BHP (1.5 mM). Berberine also attenuated the t-BHP-induced depletion of glutathione (GSH) and induced a high level of DNA repair synthesis. The in vivo study showed that the intraperitoneal pretreatment with berberine (0.5 and 5 mg/kg) for 5 days before a single dose of t-BHP (0.1 mmol/kg) significantly lowered the serum levels of hepatic enzyme markers (ALT and aspartate aminotransferase) and reduced oxidative stress in the liver. The histopathological evaluation of the livers revealed that berberine reduced the incidence of liver lesions, including hepatocyte swelling, leukocyte infiltrations, and necrosis induced by t-BHP. These results lead us to speculate that berberine may play a chemopreventive role via reducing oxidative stress in living systems.

Leber's hereditary optic neuropathy mutations in Korean patients with multiple sclerosis

Several different mitochondrial DNA (mtDNA) sites for mutations of Leber's hereditary optic neuropathy (LHON) have been reported to be present in patients with multiple sclerosis (MS). To further study this association of LHON and MS in the Korean population, we tested 20 MS patients for the presence of mtDNA mutations at nucleotide (nt) 11778 in all 20 patients, and at nt 14484, nt 3460 and nt 15257 in 15, 12 and 12 patients, respectively. However, none of the MS patients exhibited any pathogenic LHON mtDNA mutations. In conclusion, we found no evidence for any association between MS and the LHON mutation in the Korean population.

Adult lymphoblastic lymphoma in Taiwan: an analysis of treatment results of 26 patients

Lymphoblastic lymphoma (LBL) frequently affects young adults and usually presents with a mediastinal mass as well as bone marrow involvement. Although the frequency of LBL in the Far East is higher than that of Western countries, no reports regarding treatment of this disease have as yet been reported. We herein report our treatment experience and verify the efficacy of the Stanford/Northern California Oncology Group (NCOG) protocol for this disease and recommend treatment strategies for LBL patients. We retrospectively reviewed the medical records of adult LBL patients treated in our hospital from 1986 to 1996. Twenty-seven patients were diagnosed to have LBL. These patients' ages ranged from 17 to 73 years old with a median of 23. Nineteen patients had an initial stage IV disease. Of the 23 cases in which immunological studies were performed, 20 proved to be of T cell lineage, 1 of B cell type, and the other 2 lacked both T and B markers. Three major chemotherapeutic regimens including prednisone, methotrexate, doxorubicin, cyclophosphamide, etoposide-mechlorethamine, vincristine, procarbazine, prednisone (ProMACE-MOPP), cyclophosphamide, hydroxydaunomycin, vincristine, prednisone (CHOP), and the Stanford/NCOG protocol were used to treat 3, 6, and 15 patients, respectively. Two other patients were treated with two different chemotherapeutic regimens, respectively. One patient was excluded for analysis because of initial treatment by surgery. The complete response (CR) rates with ProMACE-MOPP, CHOP, and the Stanford/NCOG regimens were 0%, 17%, 80% and median overall survival 9, 8.5, and 15 months, respectively. Five patients with stage II-III diseases achieved long-term disease-free survival of 11-36 months with the Stanford/NCOG protocol with a median follow-up of 24 months. Four patients in late stage or relapse received allogeneic bone marrow transplantation (BMT). Two of them obtained long-term disease-free survival. Two other patients in CR were treated with high-dose chemotherapy (HDCT) supported with autologous BMT and peripheral blood stem cell transplantation (PBSCT), respectively. The patient receiving HDCT with autologous PBSCT died of LBL relapse 6 months after transplantation. The other patient undergoing HDCT with autologous BMT died of fulminant hepatitis 5.5 months after transplantation. The median overall survival of all these 26 patients was 12 months. B symptoms and treatment without the Stanford/NCOG protocol were found to have significantly negative impacts on both patients' overall and progression-free survivals. Our results suggest that the Stanford/NCOG protocol may be an effective chemotherapy for adult LBL and may provide long-term remission for patients in an early stage of disease. For those patients with LBL in an advanced stage or in relapse, HDCT with allogeneic or autologous BMT is probably the treatment of choice.

Stromelysin gene transfer into cultured human trabecular cells and rat trabecular meshwork in vivo

PURPOSE

To determine whether stromelysin gene can be introduced into and expressed in the cultured human trabecular cells as well as in the rat eye in vivo through means of a recombinant replication-deficient adenovirus.

METHODS

Stromelysin cDNA was obtained by reverse transcription-polymerase chain reaction with mRNA extracted from the cultured human trabecular cells after induction with interleukin 1alpha. Adenovirus vector that contains stromelysin cDNA was constructed by cotransfection of pJM17 and pDeltaA.CMV-str into the 293 cells. The expression of stromelysin in the cultured human trabecular cells was assayed by Western blot and zymography. The expression of stromelysin in the trabecular meshwork of the rat eyes was detected by in situ hybridization and immunohistochemistry.

RESULTS

The constructed adenovirus vector contained stromelysin cDNA, but no E1 region. Western blot and zymogram revealed that the stromelysin could be expressed and that it possessed enzymatic activity in cultured human trabecular cells. In situ hybridization and immunostaining of the stromelysin showed that the complete form of stromelysin was expressed in the trabecular meshwork, the iris, and the uveoscleral outflow pathway of the rat eye.

CONCLUSIONS

Stromelysin, a functional gene, can be transferred in vivo into rat eyes and in vitro into cultured human trabecular cells using a replication-deficient adenovirus vector. This shows the possibility of gene therapy in glaucoma.

Studies on anthracenes. 2. Synthesis and cytotoxic evaluation of 9-acyloxy 1,8-dichloroanthracene derivatives

The synthesis and cytotoxic evaluation of 9-acyloxy 1,8-dichloroanthracene derivatives are described. The system selectively reduces the carbonyl group flanked by the peri substituents of the anthracenediones to give the corresponding 1,8-dichloro-9(10H)-anthracenone. Simple acylation of anthracenone occurred with appropriate acyl chlorides in CH2Cl2 with a catalytic amount of pyridine to give the 9-acyloxy-1,8-dichloroanthracene derivatives. Considerable interest has developed in the mechanism of how anthracenones achieve this desirable selectivity. These compounds were evaluated in vitro for their ability to inhibit the growth of human oral epidermoid carcinoma cells (KB cell line), human cervical carcinoma cells of ME 180 (GBM 8401) and Chinese hamster ovary (CHO) cells, respectively, as compared to mitoxantrone. The in vitro cytotoxicity evaluation of 9-acyloxy 1,8-dichloroanthracenes against these above cell lines revealed for most of the compounds a cytotoxic potency lower than that of mitoxantrone. The most active compounds were thus selected for further in vitro biological evaluation and structural modification.

Different risks of symptomatic brain necrosis in NPC patients treated with different altered fractionated radiotherapy techniques

PURPOSE

To report our observation of excessive temporal lobe necrosis in nasopharyngeal carcinoma (NPC) patients treated with 160 cGy b.i.d. radiotherapy technique. During the same period, patients treated with 120 cGy b.i.d. have not shown a similar tendency. Our experience may be useful for designing unconventional radiotherapy regimens for NPC patients.

METHODS AND MATERIALS

During the period from October 1991 to January 1998, 81 M0, previously untreated NPC patients completed altered fractionated radiotherapy. Seventy patients were treated with the hyperfractionated technique, and 11 were treated using the accelerated-hyperfractionated scheme. Hyperfractionated radiotherapy was delivered using 120 cGy b.i.d. separated by 6-h intervals throughout the course. A minimum tumor dose of 8000 cGy was the standard dose over an 8-week period. With the accelerated-hyperfractionated scheme, 160 cGy was given twice daily, also with an interval of 6 h. The minimum tumor dose ranged between 6840 and 7640 cGy, with 7 of the 11 patients receiving 7000 cGy. The arrangement of portals was the same for both regimens. The follow-up period for patients alive was from 32 to 102 months with a median of 61 months for the hyperfractionated patients. For the accelerated-hyperfractionated group, it ranged from 67 to 82 months with a median of 72 months. No patient was lost to follow-up.

RESULTS

At the time of analysis, 49 of the 70 patients in the hyperfractionated group were alive. In the accelerated group, 8 of the 11 patients were alive. The estimated radiation dose to the temporal lobe for the hyperfractionated group was 6000-7440 cGy with a median of 7080 cGy. For the accelerated-hyperfractionated group, the dose range was 4480-6700 cGy with a median of 6400 cGy. Of the 70 patients treated with hyperfractionated radiotherapy, none developed symptomatic brain necrosis, despite the higher total dose to the temporal lobe in general. In contrast, 3 of the 11 (27%) patients irradiated using the accelerated-hyperfractionated regimen suffered from temporal lobe necrosis at 16, 19, and 40 months after completion of radiotherapy.

CONCLUSION

An excessive incidence of temporal lobe necrosis was noted when an accelerated-hyperfractionated regimen with 160 cGy b.i.d. was used in NPC patients with a median brain dose of 6400 cGy. There has been no such event in patients treated using a hyperfractionated regimen with 120 cGy and a median brain dose of 7000 cGy. The real causes of this discrepancy are not known. However, a high sensitivity of the human brain to a change in fraction size may play a role.

Studies on anthracenes. 3. Synthesis, lipid peroxidation and cytotoxic evaluation of 10-substituted 1,5-dichloro-9(10H)-anthracenone derivatives

The synthesis of a series of 1,5-dichloro-9(10H)-anthracenones bearing O-linked and N-linked substituents in the 10-position are described. Previous studies have shown that 9-acyloxy 1,5-dichloroanthracenes and 9-acyloxy 1,8-dichloroanthracenes displayed a potential cytotoxic effect. These results have encouraged us in further investigation of potential anthracenone derivatives. Therefore, a series of 10-substituted 1,8-dichloro-9(10H)-anthracenone derivatives were synthesized. These compounds were evaluated for their ability to inhibit the growth of human oral epidermoid carcinoma cells (KB cell line), human cervical carcinoma cells of ME 180 (GBM 8401) and Chinese hamster ovary (CHO) cells, respectively. Compounds 3c and 4c of this series compare favorably in the KB cellular assay with mitoxantrone. Compound 4c showed combined inhibitory action against KB, GBM and CHO cell growth, respectively. In addition, redox property of the compounds for the inhibition of lipid peroxidation in model membranes was determined. Compounds 4b and 4d exhibited stronger antioxidant activity than ascorbic acid, (+)-alpha-tocopherol and mitoxantrone, respectively.

Comparison between anisometropic and strabismic amblyopia using functional magnetic resonance imaging

AIMS

To assess calcarine activation with functional magnetic resonance imaging (fMRI) in patients with anisometropic and strabismic amblyopia.

METHODS

14 amblyopes (eight anisometropic and six strabismic) were studied with fMRI using stimuli of checkerboards of various checker sizes and temporal frequencies. While T2* weighted MRI were obtained every 3 seconds for 6 minutes, patients viewed the stimuli monocularly with either the amblyopic or sound eye.

RESULTS

Amblyopic eyes showed reduced calcarine activation compared with contralateral sound eyes in fMRI in all subjects. The calcarine activation from amblyopic eyes in anisometropic amblyopes was more suppressed at higher spatial frequencies, while that from amblyopic eyes in strabismic amblyopes was more suppressed at lower spatial frequencies.

CONCLUSION

These results suggest that fMRI is a useful tool for the study of amblyopia in humans. The calcarine activation via amblyopic eyes because of anisometropia or strabismus has different temporospatial characteristics, which suggests differences in the neurophysiological mechanisms between two types of amblyopia.

Studies on anthracenes. 1. Human telomerase inhibition and lipid peroxidation of 9-acyloxy 1,5-dichloroanthracene derivatives

The synthetically useful approaches to 9-acyloxy 1,5-dichloroanthracene derivatives are reported. The system selectively reduces the carbonyl group flanked by the peri substituents of the anthracenediones to give the corresponding 1,5-dichloro-9(10H)-anthracenone. Simple regioselective acylation of anthracenone is applied with appropriate acyl chlorides in CH2Cl2 with catalytic amount of pyridine to give the novel 9-acyloxy 1,5-dichloroanthracene derivatives. Considerable interest has developed in the mechanism of how anthracenone achieves this desirable selectivity. In an attempt to understand the mechanism of this reaction, solid-state structures of anthracene derivatives have been obtained. In addition, the inhibition of lipid peroxidation in model membranes was determined as was their ability to inhibit the telomere-addition function of the human telomerase enzyme together with their inhibition of the Taq polymerase enzyme. In contrast to (+)-alpha-tocopherol, 3b, 3c, 3d, 3g, and 3i do not enhance lipid peroxidation in model membranes. Implications for 9-acyloxy 1,5-dichloroanthracene analogues as potential anticancer agents are discussed.

Binocularity and spatial frequency dependence of calcarine activation in two types of amblyopia

OBJECTIVE AND BACKGROUND

Strabismus and anisometropia early in life frequently causes monocular amblyopia. Activation of the visual cortex is compared between the two types of amblyopia to elucidate differences in the pathogenetic mechanism of the disease.

METHODS

Using an EPI gradient echo sequence in 1.5T MRI, calcarine activation by monocular viewing of checkerboard patterns with reversal was examined in terms of binocularity of the activation and dependence on the spatial frequency of the stimuli.

RESULTS

First, the proportion of voxels activated by both normal and amblyopic eye monocular stimulations is lower in the strabismic group than in the anisometropic group. Second, the activation by higher-spatial-frequency stimuli is reduced in the anisometropic group, but not in the strabismic group.

CONCLUSIONS

These findings from the human visual cortex are consistent with the view proposed based on animal research that the loss of binocular interaction and the undersampling of high-spatial-frequency components of visual stimuli are each one of the underlying changes in strabismic and anisometropic amblyopia, respectively.

A randomized comparison of prism adaptation and augmented surgery in the surgical management of esotropia associated with hypermetropia: one-year surgical outcomes

OBJECTIVE

To compare motor and sensory 1-year surgical outcomes in patients with hypermetropic esotropia, managed with either augmented surgery based on the average of the near deviation with and without correction or preoperative prism adaptation.

METHODS

Forty-three patients with hypermetropic esotropia without distance-near disparity entered a randomized prospective evaluation of augmented surgery (group A, 27 patients) versus prism adaptation (group P, 16 patients). The formula for augmenting the amount of the rectus muscle recession was based on the average of the near deviation with and without correction in group A and the prism-adapted angle of deviation in group P. During prism adaptation, 9 of 16 patients in group P responded to prism. Motor and sensory outcomes of the Worth 4-dot test at 6 and 0.33 m and the Titmus stereotest were evaluated 1, 3, 6, and 12 months after surgery.

RESULTS

Postoperative deviations of 8 PD or less at distance were achieved in 24 of 27 patients (89%) of group A and in 7 of the remaining 8 patients (88%) of prism responders and in all 7 prism nonresponders (100%) in group P. No significant difference existed between groups A and P, as well as between the prism responders and prism nonresponders in group P in terms of near and distance deviation 1 year after surgery. The sensory outcomes improved over time in group A and prism responders.

CONCLUSION

There were no significant differences in the surgical outcomes between each group. However, the small sample size may limit the power to detect any statistically significant differences.

Spontaneous resolution of infantile esotropia

PURPOSE

To report the spontaneous resolution of infantile esotropia in 3 patients.

METHODS

The clinical histories and the results of ophthalmologic examinations in 3 patients with infantile esotropia were reviewed and analyzed with reference to the literature.

RESULTS

All 3 patients with infantile esotropia were diagnosed with 25 to 30 PD of esotropia before the age of 6 months. All of them had insignificant refractive errors. Against medical advice, they were not brought in for follow-up examinations. At the age of 34 months to 59 months, the esotropia of the patients had changed into exophoria, esophoria less than 4 PD, or orthophoria. All patients eventually showed dissociated vertical deviation and overaction of the inferior oblique muscles. Of the 2 cooperative patients, 1 consistently identified Titmus stereograms with 3000 seconds of arc and fused Worth 4 dots at near and at distance. The other patient could not identify stereo targets and suppressed one eye on Worth 4 testing at distance, though she showed no suppression at near.

CONCLUSION

In these cases, infantile esotropia with a relatively small angle may spontaneously resolve without any treatment. However, all these patients showed poor stereoacuity, dissociated vertical deviation, and overaction of the inferior oblique muscles.

A case of Marcus Gunn jaw winking and pseudo inferior oblique overaction

PURPOSE

To report the association of Marcus Gunn jaw-winking phenomenon and pseudo inferior oblique overaction.

METHODS

Case report.

RESULTS

A 21-year-old woman presented with right eyelid elevation on the chewing movement since infancy. Examination showed that both Marcus Gunn jaw-winking phenomenon and pseudo inferior oblique overaction coexist in this patient.

CONCLUSION

The association of Marcus Gunn jaw winking and pseudo inferior oblique overaction in one patient is reported. This coexistence in our case may provide some support to the existing concept that both phenomena are caused by an ocular aberrant innervation.