Absorption spectroscopy of gold nanoisland films: optical and structural characterization

Nanoisland films prepared by annealing thin gold films at high temperatures were imaged using scanning electron microscopy (SEM) and atomic force microscopy, and optically characterized through absorption spectroscopy. Thin gold films of effective thicknesses 2, 5 and 7 nm annealed at 500, 700 and 900 degrees C were fabricated and studied experimentally. The measured absorption characteristics in support of theoretical calculations showed that the shapes of gold islands were partial spheres. The position of the peak absorption wavelength measured with s-polarized light or at normal incidence confirmed that the island shape grew from a near-hemisphere towards a sphere with increasing annealing temperature. The SEM images confirmed that the size of islands increased from 15 nm in diameter to 40 nm in diameter as film thickness increased from 2 to 5 nm. The affect of the index of the substrate material on absorption characteristics were also studied by comparing the absorption spectra of gold island films on quartz and LaSF15 glass substrates. The use of gold nanoisland films for preparing localized surface plasmon resonance substrates was suggested as they held advantages over the gold colloid films.

Diagnosis and treatment of obscure gastrointestinal bleeding using combined capsule endoscopy and double balloon endoscopy: 1-year follow-up study

BACKGROUND AND STUDY AIMS

Several studies have shown the value of capsule endoscopy and double balloon endoscopy (DBE) in small-intestinal bleeding. The purpose of this study was to evaluate the impact of capsule endoscopy results on subsequent DBE examination, and the 1-year clinical outcome of this combined approach in patients with obscure gastrointestinal bleeding (OGIB).

PATIENTS AND METHODS

A total of 45 consecutive patients with OGIB underwent capsule endoscopy. Patients with positive capsule endoscopy results underwent DBE for biopsy or therapy, and those with negative results underwent further assessment for possible diagnostic misses on capsule endoscopy. Tumors, ulcerations, and vascular lesions were considered as sources of bleeding. Diagnoses of OGIB lesions and clinical outcome were assessed 1 year after these examinations.

RESULTS

Responsible lesions were found in 22 patients (49 %): 19 lesions in 18/45 patients (40 %) undergoing capsule endoscopy, and 18/36 patients (50 %) undergoing subsequent DBE. In all, 10 tumors, nine vascular lesions, and four ulcerations were found. In two patients, vascular lesions were only later diagnosed by conventional methods (4 %). Capsule endoscopy results guided our choice of the proper DBE model for successful therapeutic intervention in five patients. Re-bleeding rates were low during 1-year follow-up of the entire group (mean follow-up, 18.8 months): 5 % in cases with positive diagnoses on capsule endoscopy and/or DBE, and 12 % in negative cases.

CONCLUSIONS

A combined approach using capsule endoscopy followed by DBE proves valuable in the diagnosis and treatment of patients with OGIB, leaves a low rate of undiagnosed bleeding sources, and has a good long-term outcome.

Effect of Common Driving Sources to the Feedback Analysis of Heart Rate Variability

Objectives : This paper examines the operational characteristics of the multivariate autoregressive analysis applied to the simultaneous recordings of the instantaneous heart rate (IHR) and the change in systolic blood pressure (SBP).

Methods : The multivariate autoregressive model has been utilized to reveal the feedback characteristics between IHR and SBP. The model assumes the presence of independent set of driving forces to activate the system. However, it is likely that the driving forces may have correlation due to the presence of a common fluctuation source. This paper examines the effect of the presence of correlated components in the driving forces to the estimation accuracy of impulse responses characterizing the feedback properties. The twodimensional autoregressive model driven bytwo correlated 1/f noises was chosen for the analysis of operational characteristics. The driving force was generated by a moving average system which simulates non-integer order integration.

Results : Computer simulation revealed that the mean square estimation errors of impulse responses sharply increase as relative power of common driving force exceeds 50%. However, the estimation accuracy and bias are found to be in permissible range in practice.

Conclusions : These findings ensure the practical validity of utilizing multivariate autoregressive models for the feedback analysis between IHR and SBP where both signals have the common driving force.

Effect of common driving sources to the feedback analysis of heart rate variability

OBJECTIVES

This paper examines the operational characteristics of the multivariate autoregressive analysis applied to the simultaneous recordings of the instantaneous heart rate (IHR) and the change in systolic blood pressure (SBP).

METHODS

The multivariate autoregressive model has been utilized to reveal the feedback characteristics between IHR and SBP. The model assumes the presence of independent set of driving forces to activate the system. However, it is likely that the driving forces may have correlation due to the presence of a common fluctuation source. This paper examines the effect of the presence of correlated components in the driving forces to the estimation accuracy of impulse responses characterizing the feedback properties. The two-dimensional autoregressive model driven by two correlated 1/f noises was chosen for the analysis of operational characteristics. The driving force was generated by a moving average system which simulates non-integer order integration.

RESULTS

Computer simulation revealed that the mean square estimation errors of impulse responses sharply increase as relative power of common driving force exceeds 50%. However, the estimation accuracy and bias are found to be in permissible range in practice.

CONCLUSIONS

These findings ensure the practical validity of utilizing multivariate autoregressive models for the feedback analysis between IHR and SBP where both signals have the common driving force.

Monocyte chemoattractant protein 1 and macrophage cyclooxygenase 2 expression in colonic adenoma

BACKGROUND AND AIMS

Cyclooxygenase 2 (COX-2) expression in subepithelial macrophages of colorectal adenoma has been suggested as the first in a series of steps leading to colorectal tumorigenesis. We tested the hypothesis that chemokines released from human colorectal adenoma epithelium might be involved in COX-2 expression in macrophages of the lamina propria.

METHODS

Endoscopic samples of sporadic colorectal adenomas were tested by enzyme linked immunosorbent assay for chemokines involved in macrophage chemotaxis. Localisation of adenoma macrophage chemoattractant protein 1 (MCP-1) and COX-2 were determined by immunohistochemistry. The effects of MCP-1, in the presence or absence of celecoxib, on COX-2 expression, and prostaglandin (PG) E(2) and vascular endothelial growth factor (VEGF) release, were examined in human macrophages isolated from peripheral blood.

RESULTS

MCP-1 levels were markedly higher in adenoma with mild-moderate dysplasia (129.7 (19.9) pg/mg protein) and severe dysplasia (227.9 (35.4) pg/mg protein) than in normal colonic mucosa (55.8 (4.2) pg/mg protein). Other chemokine levels, macrophage inflammatory proteins (MIP)-1alpha and MIP-1beta, and the chemokine regulated on activation of normal T cell expressed and secreted (RANTES) did not vary significantly between adenoma and normal mucosa. MCP-1 levels in both adenoma and normal colonic mucosa increased significantly three hours after tissue cultivation in vitro. MCP-1 immunoreactivity was restricted to the adenoma epithelium, with no reactivity seen in adjacent normal epithelial cells. MCP-1 stimulated COX-2 expression and PGE(2) and VEGF release in human macrophages. Celecoxib, a selective COX-2 inhibitor, inhibited MCP-1-induced PGE(2) and VEGF release in macrophages. Addition of exogenous PGE(2) reversed this inhibitory effect on VEGF release, suggesting that MCP-1 in adenoma epithelial cells might be involved in COX-2 expression and subsequent macrophage activation.

CONCLUSIONS

MCP-1 in colorectal adenoma epithelial cells might be involved in macrophage migration and COX-2 expression, leading to the subsequent development of colonic adenoma.

Primary invasive micropapillary carcinoma of the colon

AIMS

Invasive micropapillary carcinoma (IMPC) is associated with frequent lymph node metastasis and adverse clinical outcome. IMPC has been reported in breast, urinary bladder, ureter, lung and parotid gland but not in colon. We present the clinicopathological features of three cases of primary IMPC of the colon with a review of the literature.

METHODS AND RESULTS

The patients (one man and two women) were 53, 67 and 68 years old, respectively. The size of the tumour ranged from 20 to 100 mm in diameter. Histologically, all cases were composed predominantly of papillary tumour cell clusters with spaces in a background of fine fibrocollagenous stroma. One of the tumours (case 1) was nearly completely composed of IMPC, but the other two were associated with foci of adenocarcinoma and concurrent mucinous carcinoma, respectively. MUC1 was positive in all cases, suggestive of reverse cell orientation which is responsible for its unique histological features.

CONCLUSIONS

We report three cases of primary IMPC of the colon. Its clinical significance remains undetermined but the presence of this component may represent a poor prognostic factor.

Low atmospheric temperature dependence on photodegradation of wood

This paper deals with the photodegradation of wood in low atmospheric temperature region (-40 to 50 degrees C), and discusses the changes in color and IR spectra. The color and IR spectra of wood hardly changed with photo-irradiation at -40 degrees C but did at -20 degrees C. Therefore, it is thought that the photo-energy causes the scission of chemical bonds or the production of radicals; however, heat energy is needed to yellow of wood (i.e., to produce quinone). In case of softwoods, the absorption of the carbonyl band consisted of two sub-bands, and the carbonyl band at around 1710 cm(-1) increased at lower temperature than that at around 1760 cm(-1) by light-irradiation. Such IR measurement due to lignin degradation means that the photodegradation of softwoods is faster than that of hardwoods. The color change by exposure to light in the low temperature was also caused by the degradation of lignin.

Purification and characterization of extracellular alkaline serine protease from Stenotrophomonas maltophilia strain S-1

AIMS

The present study was conducted by screening soil bacteria in an attempt to isolate a bacterium that produced extracellular alkaline protease, and for purification and characterization of the protease.

METHODS AND RESULTS

Soil bacteria were screened by growth on casein as the sole carbon source. Characterization of a strain isolated from soil of Abashiri, Japan indicated a taxonomic affiliation to Stenotrophomonas maltophilia, and was named S-1 strain. The purified S-1 protease, designed S. maltophilia Protease-1 (SmP-1), exhibited an optimal pH of 12.0, optimal reaction temperature of 50 degrees C and a molecular mass of approximately 40 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The cleavage sites of the oxidized-insulin B chain by SmP-1 were identified as Leu6-Cys7, Cys7-Gly8, Tyr16-Leu17 and Leu17-Val18. The N-terminal amino acid sequence of the purified alkaline protease was determined as NH2-SASAPMVSGVAALVLE.

CONCLUSION

A novel extracellular alkaline serine protease was isolated from S. maltophilia strain S-1. The optimal pH of the proteolytic activity was pH 12.0.

SIGNIFICANCE AND IMPACT OF THE STUDY

The extremely high optimal pH and heat stability of the alkaline serine protease SmP-1 might make it widely applicable to food and other industries.

Phenylalanine ammonia-lyase modified with polyethylene glycol: potential therapeutic agent for phenylketonuria

Phenylketonuria (PKU) is an autosomal recessive genetic disease caused by the defects in the phenylalanine hydroxylase (PAH) gene. Individuals homozygous for defective PAH alleles show elevated levels of systemic phenylalanine and should be under strict dietary control to reduce the risk of neuronal damage associated with high levels of plasma phenylalanine. Researchers predict that plant phenylalanine ammonia-lyase (PAL), which converts phenylalanine to nontoxic t-cinnamic acid, will be an effective therapeutic enzyme for the treatment of PKU. The problems of this potential enzyme therapy have been the low stability in the circulation and the antigenicity of the plant enzyme. Recombinant PAL originated from parsley (Petroselinum crispum) chemically conjugated with activated PEG2 [2,4-bis(O-methoxypolyethyleneglycol)-6-chloro-s-triazine] showed greatly enhanced stability in the circulation and was effective in reducing the plasma concentration of phenylalanine in the circulation of mice. PEG-PAL conjugate will be an effective therapeutic enzyme for the treatment of PKU.

Can ataxin-2 be down-regulated by allele-specific de novo DNA methylation in SCA2 patients?

Spinocerebellar ataxia type 2 (SCA2) is caused by a CAG trinucleotide repeat expansion within the coding region of the ataxin-2 gene. Affected individuals typically have between 34 and 57 CAG repeats. Signs of the disorder generally begin in adulthood and include progressive ataxia, dysarthria, tremor, hyporeflexia, and slow saccades. As with other trinucleotide repeat disorders, SCA2 exhibits an inverse correlation between the size of the CAG repeat and the age at onset of clinically detectable disease, with neonatal cases of SCA2 being reported in individuals harboring over 200 CAG repeats. However, a wide range of age at onset is typically observed, especially in individuals with < 40 CAG repeats. CAG repeat number alone explains approximately 25-80% of the variability. In this paper, we hypothesize that the level of mutant ataxin-2 protein in affected cells contributes to these differences. One of the mechanisms that might influence this protein levels is de novo DNA methylation, which would specifically target the allele with the expanded CAG repeat leading to transcriptional silencing. Consequently, the symptoms of SCA2 would occur later in the patient's life history. Our postulations, as well as those previously reported to account for the phenotype of SCA2, are discussed.

Sarcoplasmic reticulum Ca2+ release is not a dominating factor in sinoatrial node pacemaker activity

Recent work on isolated sinoatrial node cells from rabbit has suggested that sarcoplasmic reticulum Ca2+ release plays a dominant role in the pacemaker potential, and ryanodine at a high concentration (30 micromol/L blocks sarcoplasmic reticulum Ca2+ release) abolishes pacemaking and at a lower concentration abolishes the chronotropic effect of beta-adrenergic stimulation. The aim of the present study was to test this hypothesis in the intact sinoatrial node of the rabbit. Spontaneous activity and the pattern of activation were recorded using a grid of 120 pairs of extracellular electrodes. Ryanodine 30 micromol/L did not abolish spontaneous activity or shift the position of the leading pacemaker site, although it slowed the spontaneous rate by 18.9+/-2.5% (n=6). After ryanodine treatment, beta-adrenergic stimulation still resulted in a substantial chronotropic effect (0.3 micromol/L isoproterenol increased spontaneous rate by 52.6+/-10.5%, n=5). In isolated sinoatrial node cells from rabbit, 30 micromol/L ryanodine slowed spontaneous rate by 21.5+/-2.6% (n=13). It is concluded that sarcoplasmic reticulum Ca2+ release does not play a dominating role in pacemaking in the sinoatrial node. The full text of this article is available at http://www.circresaha.org.

Influence of alcohol consumption on the association between serum lipids and colorectal adenomas

BACKGROUND

There have been no reports that low serum cholesterol levels increase the risk of colorectal adenoma, although many studies have shown that they do increase the risk of colorectal cancer. Alcohol intake, which is associated with a risk of colorectal adenomas, and serum cholesterol levels are closely related. The purpose of this study was to evaluate the influence of alcohol consumption on the association between serum cholesterol levels and colorectal adenoma.

METHODS

The subjects were 1,349 male patients who underwent both barium enema examination and total colonoscopy. They answered a questionnaire regarding their alcohol consumption history, and their blood samples were analysed. The subjects were divided into three groups: those with no tumour (with neither adenoma nor adenocarcinoma), those with adenoma and those with adenocarcinoma. Among the groups, the serum total cholesterol and triglyceride levels were compared in all the patients, in the patients who did not drink daily and in the patients who did.

RESULTS

In all the patients, the serum cholesterol and triglyceride levels did not differ between the patients with and those without adenoma. In the daily drinkers, the serum cholesterol and triglyceride levels were significantly lower in patients with adenoma than in those without.

CONCLUSIONS

Significantly lower levels of serum cholesterol and triglycerides were found in daily drinkers with adenoma than in those without.

Treatment of oligoasthenozoospermia with tranilast, a mast cell blocker, after long-term administration

The authors retrospectively examined whether long-term administration of tranilast improves semen parameters in severe oligoasthenozoospermia. Fifty-two patients presenting with sperm concentration of less than 10 x 10(6) sperm/mL were enrolled. Subjects were partitioned into 3 groups as follows: patients displaying an atrophic testis with elevated (FSH) (group 1), patients exhibiting normal testicular volume with elevated FSH (group 2), and patients with normal testicular volume and normal FSH levels (group 3). Tranilast (300mg/day) was administered until pregnancy was achieved or for a period of up to 12 months. Sperm concentration was significantly increased at 3 months in 16 subjects (44%) in groups 1 and 3. In group 2, sperm concentration was increased at 12 months (5 of 16 subjects; 31%). Total sperm count was obviously elevated at 3 months in groups 1 and 2, and at 6 months in group 3. Six pregnancies were achieved via natural intercourse. Tranilast, a mast cell blocker, demonstrates a certain clinical benefit in terms of improvement of semen parameters involving severe oligoasthenozoospermia, but it does not appear to afford clinical benefit in long-term administration.

An ARL1 mutation affected autophagic cell death in yeast, causing a defect in central vacuole formation

When the cdc28 strain of Saccharomyces cerevisiae is incubated at restrictive temperatures, the yeasts digest themselves in 7 days by activating autophagic machinery. In parallel, the cell-proliferative activity decreases progressively after about 48 h. We have previously referred to this phenomenon as autophagic death. In the present study, we isolated and characterized a recessive mutant strain, dlp2, which delays the progression toward autophagic death. The cdc28 dlp2 cells contain many small vesicles instead of the large central vacuoles that are usually found in parental cdc28 cells. We showed that the dlp2 phenotype results from the presence of a single mutation in the gene ARL1 (ADP-ribosylation factor-like protein 1). Morphological and biochemical analyses of cdc28 dlp2 suggested that a defect in central vacuole formation is caused by aberrant membrane trafficking, although the protein-sorting to vacuoles is not affected. After a shift to a restrictive temperature, the components of the cytoplasm and nucleus of cdc28 dlp2 were condensed, with an accompanying formation of vesicles in the periphery (epiplasm) of the cells rather than an activation of the autophagic machinery. Introducing this ARL1 mutation into the normal ARL1 locus of the wild-type W303 strain again inhibited the progression of apoptotic cell death due to a defect in vacuole formation, which in this case was induced by the proapoptotic protein Bax. Thus, the ARL1 gene plays an important role in the formation of central vacuoles and in the progression of programmed cell death induced by cell-cycle arrest or Bax. These results suggested the presence of a programmed-cell death machinery in yeast that is similar to that related to the Type II cell death of mammalian cells characterized by autophagocytosis.

Clinical study of transitional cell carcinoma of the prostate associated with bladder transitional cell carcinoma

BACKGROUND

Transitional cell carcinoma of the prostate in patients with bladder cancer appears to influence the prognosis and affects the decision about therapeutic modality. Therefore, it is important to characterize transitional cell carcinoma associated with bladder cancer.

METHODS

From April 1980 to December 1998, 81 male patients underwent total cystoprostatectomies for transitional cell carcinoma of the bladder. The 81 cystoprostatectomy specimens were examined to clarify the characteristics of prostatic involvement by transitional cell carcinoma. The extent, origin, mode of spread and risk factor of prostatic involvement as well as the prognosis were investigated. In 13 of 15 patients with prostatic involvement the prostate was examined by sequential step sections.

RESULTS

Prostatic involvement was observed in 15 of 81 patients (18.5%). Prostatic urethral involvement, invasion to prostatic duct/acinus, prostatic stromal invasion and extraprostatic extension and/or seminal vesicle involvement were recognized in 12 (80%), 14 (93.3%), six (40%), and five (33.3%) of the 15 patients, respectively. Twelve of the 15 patients (80%) with prostatic involvement had papillary or non-papillary tumors (i.e. carcinoma in situ) both in the prostatic urethra and prostatic duct. In 10 of these 12 patients (88.3%), there was contiguity between prostatic urethral and ductal tumors. Seven of the 23 patients (30.4%) with carcinoma in situ of the bladder showed prostatic involvement, which increased to 50% in the presence of carcinoma in situ of the trigone or bladder neck.

CONCLUSIONS

Eighty per cent of the patients with prostatic involvement showed papillary or non-papillary tumors both in the prostatic urethra and prostatic duct. There was a high level of contiguity between both tumors. Patients with carcinoma in situ of the trigone or bladder neck revealed significantly higher incidence of prostatic involvement.

Endoscopic ureteral incision using the holmium:YAG laser

BACKGROUND

We reviewed the results of endoscopic ureteral incision for benign ureteral stricture, ureteropelvic junction obstruction and ureteroenteroanastomotic stricture using the holmium laser.

METHODS

We carried out endoscopic ureteral incision using the holmium laser through an 8-Fr semirigid or 6.9-Fr flexible ureteroscope on 17 ureters in 15 patients. Balloon dilatation was not necessary before insertion of the ureteroscope. The stricture was incised with the holmium laser using a 200-365 microm fiber through the working channel of the ureteroscope. After completion of the incision, a 12-Fr double-J catheter was left for 6 weeks. Thereafter patients were followed by renal scan and/or ultrasound and excretory urography at 3-6 month intervals.

RESULTS

The mean operative time was 65 min (18-135 min). The stricture resolved completely in 86.7% of cases at an average follow up of 20.5 months (11-32 months).

CONCLUSIONS

The holmium laser endoscopic ureteral incision was associated with a good outcome in our series. We recommend this procedure to be employed initially because it is less invasive and has a favorable outcome.

Analysis of the upstream regulatory region of the GTS1 gene required for its oscillatory expression

The protein level of the GTS1 gene product (Gts1p) fluctuated during the oscillation of energy metabolism in continuous culture of the yeast Saccharomyces cerevisiae. Here, we found that the GTS1 mRNA level oscillated with the same periodicity as the metabolic oscillation, suggesting that the expression of GTS1 was regulated at the transcriptional level. As the 5'-upstream sequence of GTS1 contains two short open-reading frames at -310 and -829 bp from the initiation codon, we determined the GTS1 promoter required for the oscillatory expression. The upstream sequence was truncated into fragments of 183, 355, 1,042, and 1,572 bp, named GTS1pr.183 and so on, and their effects on the expression of lacZ as a reporter gene and the GTS1 gene itself were examined. The beta-galactosidase activity and Gts1p level oscillated in the continuous cultures when genes were expressed under the control of GTS1pr.183 but not GTS1pr.355. The disappearance of the metabolic and cell-cycle oscillations in the GTS1-deleted mutant was rescued by the transformation with GTS1pr.183-GTS1 but not with GTS1pr.355-GTS1. However, the stress-resistance oscillations were not found in the cells transformed with GTS1pr.183-GTS1, differing from the case of GTS1pr.1042-GTS1 reported previously [Wang et al. (2001) FEBS Lett. 489, 81-86]. Thus, we suggest that the 183-bp upstream sequence of GTS1 is basically required for the metabolic oscillation, while the 1,042-bp upstream sequence is required for oscillations of stress resistance.

Thoracoscopic lung volume reduction surgery for pulmonary emphysema patients with severe hypercapnia

OBJECTIVES

We assessed whether hypercapnia patients with an extremely high level of PaCO2 > or = 60 mmHg were suitable candidates for lung volume reduction in the treatment of severe pulmonary emphysema.

METHODS

Of 65 patients undergoing lung volume reduction surgery between May 1993 and August 1997, 6 (9.23%) who had a preoperative rest room air blood gas level of PaCO2 > or = 60 mmHg were selected for study. All patients underwent video-assisted thoracoscopic surgery. Of the 6 with severe hypercapnia, 5 underwent the unilateral procedure and 1 the bilateral procedure.

RESULTS

All severe hypercapnia patients showed significant clinical improvement. When assessed at 3 to 6 months after lung volume reduction surgery, significant improvements were seen in mean forced expiratory volume in 1 second (preop: 0.44 +/- 0.04 L; postop: 0.74 +/- 0.20 L; p < 0.01), for a magnitude improvement of 69.8%, and in trapped gas volume (preop: 3.28 +/- 1.11 L; postop: 1.61 +/- 1.02 L; p < 0.05). Arterial blood gas analysis showed significant improvement in PaO2 from 51.1 +/- 6.68 mmHg to 69.8 +/- 7.87 mmHg (p < 0.001) with a decrease in PaCO2 from 70.4 +/- 9.41 mmHg to 46.9 +/- 3.44 mmHg (p < 0.01). Postoperative follow-up averaged 55 months (43-69 months). All but 1 patient remain alive and well.

CONCLUSION

Patients with severe pulmonary emphysema accompanied by hypercapnia can gain relief and a better quality of life through volume reduction surgery and should not be excluded from surgical treatment simply based on this condition. Selection should involve a comprehensive view of the patient's condition that includes criteria such as the results of radiographic diagnosis and detailed pulmonary function tests.

Stereoselectivity and regioselectivity in the segment-coupling Prins cyclization

The scope of the segment-coupling Prins cyclization has been investigated. The method is outlined in Scheme 1 and involves esterification of a homoallylic alcohol (1), reductive acetylation to give the alpha-acetoxy ether (3), and cyclization on treatment with a Lewis acid to produce a tetrahydropyran (4). Alkene geometries dictate the product configurations, with E-alkenes leading to equatorial substituents and Z-alkenes leading to axial substituents (Table 1). Not unexpectedly, applying the method to allylic alcohols leads to fragmentation rather than a disfavored 5-endo-trig cyclization. Dienols in which one alkene is allylic and the other alkene is homoallylic cyclize efficiently and produce the tetrahydropyrans 49-54, Table 3. Dienols with two homoallylic alkenes cyclize with modest to high regioselectively, generating tetrahydropyrans 40-45, Table 2. The relative rates for cyclization decrease in the order of vinyl > Z-alkene > E-alkene > alkyne. The configurations of the products are consistent with cyclization via a chair conformation, Figure 1. The 2-oxonia Cope rearrangement may be a factor in the regioselectivity of diene cyclizations and in the erosion of stereoselectivity with Z-alkenes. This investigation establishes the stereoselectivity and regioselectivity for a number of synthetically useful segment-coupling Prins cyclizations.

[A case of choroidal hemangioma with bullous exudative retinal detachment treated successfully by transpupillary thermotherapy]

BACKGROUND

Choroidal hemangioma associated with bullous retinal detachment may be difficult to treat, due to varying results with conventional laser photocoagulation, radiotherapy, or surgical drainage. Here we report on a case of extensive bullous retinal detachment secondary to circumscribed choroidal hemangioma that was resolved after combined treatment with vitrectomy, silicone oil tamponade, and transpupillary thermotherapy.

CASE

A 29-year-old woman presented with a large choroidal hemangioma in her right eye associated with serous retinal detachment. The tumor measured 8 disc diameters in size and was located in the inferotemporal macula, abutting the fovea.

RESULTS

Laser photocoagulation of the tumor was unsuccessful in inducing absorption of subretinal fluid. Because of progressive bullous retinal detachment, surgery was performed consisting of external drainage of subretinal fluid, vitrectomy, endolaser photocoagulation of the tumor, and silicone oil tamponade. The silicone oil was removed four weeks postoperatively at which time almost complete resolution of the retinal detachment was observed. However, retinal detachment recurred eight weeks later, and transpupillary thermotherapy was then applied to the tumor. By four weeks after transpupillary thermotherapy, total reabsorption of subretinal fluid, visual acuity improvement, and decreased height of the choroidal hemangioma were noted.

CONCLUSION

Transpupillary thermotherapy is an effective treatment for serous retinal detachment associated with choroidal hemangioma.

Holmium:YAG laser endoureterotomy in the treatment of ureteroenteric stricture following Indiana urinary diversion

A 57-year-old man who had received radical urethrocystectomy and Indiana urinary diversion 6 months earlier was treated for ureteroenteric anastomosis stricture (left side) using a Holmium:YAG laser via antegrade approach. The availability of small (6.9 Fr) flexible ureteroscope, as well as the use of the Holmium:YAG laser has facilitated the ability to precisely incise the stricture under direct endoscopic visualization. The technique is described for laser endoureterotomy in a patient with ureteroenteric stricture following Indiana urinary diversion.

The treatment with tranilast, a mast cell blocker, for idiopathic oligozoospermia

Although many drug treatments have been reported to theoretically improve semen parameters in male infertility, a standard method has not been established. The authors examined whether tranilast, a mast cell blocker, improves fertility and/or semen parameters in severe oligozoospermia. Seventeen patients with a sperm density of less than 10 x 10(6) sperm/mL and their fertile partners were enrolled in this study. Patients were prescribed tranilast 300 mg/day for at least 12 weeks. Semen and blood samples were collected before and after the prescription of tranilast for 12 weeks. Semen parameters, serum gonadotropins, luteinizing hormone, follicle-stimulating hormone, serum testosterone, and testicular size were evaluated. One patient complained of mild drowsiness during treatment. The sperm count was significantly increased after administration of tranilast in 7 patients (41.1%), although sperm motility was not altered. Semen volume and normal morphology were also unaltered. Three pregnancies were achieved. Endocrine profile and testicular size were unchanged. Tranilast, a mast cell blocker, is clinically useful for the treatment of severe idiopathic oligozoospermic men.

Oxidation-active flavin models: oxidation of alpha-hydroxy acids by benzo-dipteridine bearing metal-binding site in the presence of divalent metal ion and base in organic solvents

The oxidizing ability of benzo-dipteridine bearing a bipyridin-6-ylmethyl moiety (4) was found to be increased with Zn(2+) by approximately 10(3)-fold for sulfite addition in MeOH and approximately 10(2)-fold for oxidation of an NADH model in MeCN. It was found for the first time that 4 is able to oxidize alpha-hydroxy acids to alpha-keto acids in the presence of a divalent metal ion such as Zn(2+), Co(2+), and Ni(2+) and an amine base in MeCN or t-BuOH, whereas benzo-dipteridine having a bipyridin-5-ylmethyl moiety (3) is unable to oxidize them under the same conditions. The oxidation reaction was kinetically investigated including the kinetic isotope effect for deuterated mandelic acids (k(H)/k(D) = 2.1-3.7) and the Hammett plots for substituted mandelic acids (V-shaped plots). In the reaction of alpha-substituted alpha-hydroxy acids such as alpha-methyl mandelic and benzylic acids with 4, novel oxidative decarboxylation was found to take place, giving acetophenone and benzophenone, respectively. The oxidation mechanism for mandelic acid was proposed to proceed via a ternary complex of 4.Zn(2+).PhCH(OH)CO(2)(-), in which alpha-oxyanion of mandelate attacks C(4a)-position of 4 to form an adduct followed by 1,2-elimination to afford benzoyl formate and 2e-reduced 4. The roles of the metal ion were proposed as follows; (i) activation of 4, (ii) substrate-binding site, and (iii) activation of the bound alpha-hydroxy acid by lowering pK(a)'s of alpha-OH and alpha-CH. This is a first example that a flavin model oxidizes alpha-hydroxy acids in the presence of a metal ion.