Inhibition of low-density lipoprotein oxidation by astaxanthin

Marine animals produce astaxanthin which is a carotenoid and antioxidant. In this study we determined the in vitro and ex vivo effects of astaxanthin on LDL oxidation. The oxidation of LDL was measured in a 1 ml reaction system consisting of increasing concentrations of astaxanthin (12.5, 25.0, 50.0 microg/ml), 400 microM V-70 (2, 2'-azobis(4-methoxy-2, 4-dimethylvaleronitrile)), and LDL (70 microg/ml protein). Astaxanthin dose, dependently significantly prolonged the oxidation lag time (31.5, 45.4, 65.0 min) compared with the control (19.9 min). For the ex vivo study 24 volunteers (mean age 28.2 [SD 7.8] years) consumed astaxanthin at doses of 1.8, 3.6,14.4 and 21.6 mg per day for 14 days. No other changes were made in the diet. Fasting venous blood samples were taken at days 0, +14. LDL lag time was longer (5.0, 26.2, 42.3 and 30.7% respectively) compared with day 0 after consuming astaxanthin at doses of 1.8, 3.6,14.4 and 21.6 mg for 14 days compared with day 0, but there was no difference in oxidation of LDL between day 0 (lag time 59.9+/-7.2 min) and day 14 (57.2+/-6.0 min) in the control group. Our results provide evidence that consumption of marine animals producing astaxanthin inhibits LDL oxidation and possibly therefore contributes to the prevention of atherosclerosis.

Matrilysin stimulates DNA synthesis of cultured vascular endothelial cells and induces angiogenesis in vivo

Matrilysin produced by human colon cancer cells may be involved in the progression and metastasis of cancer. In the present study, we investigated the association of matrilysin with angiogenesis. One microgram of recombinant matrilysin is confirmed to have increased [3H]-thymidine uptake in human umbilical vein endothelial cells. Then we used micro encapsulation and a mouse hemoglobin enzyme-linked immunosorbent assay system for in vivo quantitation of angiogenesis with BALB/c nu/nu athymic mice. Hundred micrograms of recombinant matrilysin induced angiogenesis to the same degree as 10 microg of basic fibroblast growth factor (bFGF). Angiogenesis was observed at the site implanted with human colon cancer WiDr cells in agarose micro beads. This was inhibited by subcutaneous injection of matrilysin-specific antisense oligonucleotide significantly by 53%. In conclusion, matrilysin may be associated with angiogenesis of human colon cancer through the direct proliferative action on endothelial cells.

Magnetic resonance imaging in the evaluation of vaginal foreign bodies in a young girl

A 7-year-old girl with foul-smelling, bloody vaginal discharge for more than 2 years was initially suspected of suffering from vaginal foreign bodies. Although plain radiography revealed no abnormal findings in the pelvis, magnetic resonance imaging (MRI) showed multiple low intensity objects and an intact vaginal wall. Four plastic toys were removed with forceps under general anesthesia. MRI is supposed to be the best technique for evaluating vaginal foreign bodies in young girls.

Inhibition of osteoclast differentiation and bone resorption by cathepsin K antisense oligonucleotides

We confirmed the expression of cathepsin K, the most abundant and specific cysteine protease found in osteoclasts, at the mRNA level in most of our cases of breast cancer, and even at the protein level in bone metastatic lesions. Therefore, we investigated the functions of cathepsin K in osteoclasts with special attention to bone metastasis from breast cancer. Mouse osteoclast-like cells (OCLs) were established by coculture of mouse bone marrow cells and osteoblastic cells. Rodent cathepsin K antisense (AS) or random control (CL) oligonucleotides were added on day 0, 3, or 6 of culture. Tartrate-resistant acid phosphatase staining confirmed the formation of OCLs after 9 d of incubation. AS treatment significantly reduced both the number of TRAP-positive cells and the percentage of multinuclear cells. For the pit-forming assay, after 9 d of incubation, mature OCLs were collected and incubated on ivory slices with AS or CL for 48 h. The antisense oligonucleotides also inhibited the bone-resorbing activity of OCLs. CL treatment did not affect either the number of TRAP-positive cells or pit formation. Cathepsin K may play important roles in bone resorption as well as in differentiation of osteoclasts. These findings indicate that the inhibition of this enzyme may prevent the development of bone metastasis from breast cancer.

Daily cocoa intake reduces the susceptibility of low-density lipoprotein to oxidation as demonstrated in healthy human volunteers

Nine male volunteers were given 36 g of cocoa powder (containing 2610 mg of polyphenols) per day with sugar and 6 volunteers received an equivalent amount of sugar for 2 weeks. Conjugated diene production in LDL induced by 2-2' azobis(4-methoxy-2,4-dimethylvaleronitrile) (V-70) and copper ion were evaluated. The lag time was significantly prolonged at 1 and 2 weeks in V-70 and at 2 weeks in copper ion after cocoa powder consumption. The level of excretion of epicatechin in urine was significantly higher in the cocoa group than that in the control group. In conclusion, the antioxidants in cocoa powder might be absorbed and increase the resistance of human LDL to oxidation.

Changes in clinicopathological findings after portal vein embolization

BACKGROUND/AIMS

Portal vein embolization is becoming more common as a method of preventing hepatic failure after an extended hepatectomy but its mechanism is not well understood. This clinicopathological study focused on its mechanism.

METHODOLOGY

Thirty patients who underwent extended hepatectomy after portal vein embolization were evaluated. Liver volume was measured before and after portal vein embolization, and histological studies were performed to examine morphological changes, morphometric parameters and apoptosis of hepatocytes.

RESULTS

The mean volume of the non-embolized lobe grew significantly from 392 to 462 mL after portal vein embolization (P < 0.0001). The hypertrophy ratio of the non-embolized lobe (100 x volume change during portal vein embolization/volume before portal vein embolization, %) was correlated closely with the volume of the non-embolized lobe before portal vein embolization (r = -0.65, P < 0.0001). Histological study showed the embolized lobe hepatocytes to be atrophic, partly necrotic and apoptotic. In the non-embolized lobe, the mean hepatocyte volume was 8686 micron 3 (control: 6544 micron 3) and the mean hepatocyte count was 109 x 10(6)/mL (control: 122 x 10(6)/mL).

CONCLUSIONS

The enlargement of the non-embolized lobe was caused by hypertrophy rather than hyperplasia suggesting hyperfunction. The resection of the atrophic embolized lobe, leaving the hypertrophic non-embolized lobe was thought to be less surgically stressful than hepatectomy without portal vein embolization.

Prenatal findings in Brachmann-de Lange syndrome

We present a case of Brachmann-de Lange syndrome, in which prenatal ultrasonographic evaluation demonstrated increased nuchal translucency, early onset of intrauterine growth retardation, and limb abnormalities in the first, second, and third trimester, respectively.

Reversal of intrapulmonary arteriovenous shunting detected by two-dimensional contrast-enhanced echocardiography after liver transplantation

BACKGROUND

Intrapulmonary arteriovenous shunting (IPS), occasionally associated with advanced liver disease, may reverse after liver transplantation (LTx). Two-dimensional contrast-enhanced echocardiography, a convenient noninvasive study, has never been used to demonstrate disappearance of IPS after LTx.

METHODS

For an 8-month-old girl undergoing living-related LTx, two-dimensional contrast-enhanced echocardiography was performed with the microbubble injection. The opacification of the microbubble in the left heart emerging within 3-6 beats after detection in the right heart was compared with that in the right heart.

RESULTS

Microbubble opacification in the left heart was almost the same as that in the right heart (grade 3) shortly after LTx. However, the contrast in the left heart diminished (grade 1) as the respiratory condition improved and subsequently disappeared (grade 0).

CONCLUSIONS

Two-dimensional contrast-enhanced echocardiography may be a feasible noninvasive method to evaluate the degree of IPS in the peritransplant period and observe disappearance of IPS after LTx.

Role of prostaglandin E2 and leukotriene B4 in skin reaction induced by transdermal application of propranolol

Dermal application of propranolol (PRL) induced formation of erythema and edema, and pseudoeosinophil infiltration in epidermis and dermis at the application site in guinea pigs. We investigated the production of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) at the application site of PRL and the role of these inflammatory chemical mediators in the occurrence of the skin reactions. PGE2 was found to be produced at the application site slightly after the accumulation of PRL released from the adhesive bandage in the patch test, and the amount of PGE2 increased continuously, with a peak value obtained at 24 h after application. The time-course changes resembled those of delta a* value, the index of erythema formation determined by colorimetric measurement, and edema formation. The production of PGE2 by dermal application of PRL was suppressed by local pretreatment with dexamethasone or indomethacin. However, no notable production of LTB4 was observed at the application site of PRL.

Does pancreatico-biliary maljunction play a role in spontaneous perforation of the bile duct in children?

Spontaneous perforation of the bile duct (SPBD) is a rare disease in children. Pancreatico-biliary maljunction (PBM) has been postulated to contribute to its etiology. We have treated three children with SPBD over 30 years, two of whom had PBM. There was one boy and two girls aged 10 months to 2 years with symptoms of abdominal distension, vomiting, abdominal pain, jaundice, and acholic stools. The diagnosis of SPBD was made by paracentesis showing biliary ascites, and primary biliary and intra-abdominal drainage was performed in all cases. The site of perforation was at the connection of the common bile duct (CBD) with the cystic duct in all cases. In two cases reflux of contrast into the pancreatic duct was noted, the common channel was long (17 and 12 mm, respectively), and the bile amylase level in the CBD was abnormally high (50,000 and 67,000 IU/l, respectively). In the third patient there was no reflux of contrast into the pancreatic duct and the bile amylase and trypsin levels in the CBD and gallbladder were not measurable. Thus, SPBD in children may not be due solely to PBM, but may involve multiple mechanisms.

[Putaminal signal hypointensity on T2 weighted MR image in a patient with corticobasal degeneration]

In the course of a 74-year-old woman with corticobasal degeneration (CBD), bilateral putaminal signal hypointensity appeared on T2 weighted MR image. This right-handed woman noticed progressive difficulty in writing and using chopsticks during two years. Neurological examination in February 1998 showed apraxia, rigidity, akinesia and myoclonus, which were more marked in the right hand side. MRI revealed atrophy of the left frontotemporal lobes. These findings were compatible to CBD. Her symptoms progressed slowly. On re-admission due to aspiration pneumonia in December 1998, she showed difficulty in swallowing and walking in addition to the signs and symptoms described above. MRI revealed bilateral putaminal signal hypointensity on T2 weighted image. In the literature, totally 9 cases in 2 reports showed similar putaminal signal hypointensity. Although this finding is unusual in CBD, advanced degenerative process in the putamen might have induced this change due possibly to the accumulation of iron secondary to the nerve cell loss.

Telomerase enzyme activity and RNA expression in adriamycin-resistant human breast carcinoma MCF-7 cells

Telomerase activity has been reported in cancer cells after treatment with antineoplastic agents. Assessment of telomerase activity could be a valuable tool to measure the reduction of aggression caused by chemotherapy. This study was designed to investigate the significance of telomerase for chemotherapy with respect to Adriamycin (ADM)-resistance. MCF-7 and its ADM-resistant line (AdrR) were treated with ADM, 5-fluorouracil (5FU) or taxotere (TAXO). Telomerase activity and human telomerase RNA component (hTR) were quantitatively measured by the telomeric repeat amplification protocol assay and RT-PCR, respectively. Cell counting and MTT assay were also performed. In MCF-7, enzyme activity was significantly reduced by ADM and 5FU treatments. In AdrR, 5FU and TAXO reduced enzyme activity, while ADM significantly increased the activity. No significant changes in hTR were seen in these two cell lines after treatment with any of these drugs. When Bcl-2 expression was examined after drug treatments, ADM increased Bcl-2 expression in AdrR cells, while not changing it in MCF-7 cells. We conclude that an unusual reaction of telomerase activity in AdrR may explain, at least in part, one of the mechanisms of the malignant biological behavior related with the drug-resistance to ADM.

Skin toxicity of propranolol in guinea pigs

The skin toxicities of propranolol were studied in guinea pigs. In the primary and cumulative skin irritation studies, the skin reactions and the histopathological changes were observed in all animals treated with propranolol, and those tended to increase with the increase of propranolol dosage. The skin reactions increased with the application times of propranolol up to 7 days in the cumulative skin irritation study. In the skin sensitization, the phototoxicity and the skin photosensitization studies, no skin reactions were observed in any animals used in the studies. These results indicate that propranolol caused skin irritation, but was negative for skin sensitization, phototoxicity and skin photosensitization in guinea pigs.

Relationship between the skin permeation movement of propranolol and skin inflammatory reactions

We studied inflammatory reactions induced by dermal application of the beta-blocker propranolol (PRL) in ethanol to guinea pigs in order to elucidate the relation of the reactions with the cumulative PRL permeating amount through the stratum corneum or the PRL content in the stripped skin, and to investigate the chemical mediators responsible for the reactions. The cumulative PRL permeating amount through the stratum corneum increased rapidly up to 2 h after dermal application, then increased linearly with time up to 24 h after application. Visual observation revealed formation of erythema and edema at the applied site of PRL, and histopathological examination revealed infiltration of pseudoeosinophiles of dermis and epidermis and degeneration/necrosis of epidermis. In general, it was considered that the duration and the extent of these reactions were dependent on the PRL dosage and application time. It was expected that the cumulative PRL permeating amount through the stratum corneum could be used to predict possible inflammatory reactions during development of transdermal drug delivery systems. On the other hand, contact of PRL with guinea pig skin tissues released histamine, and intradermal injection of PRL caused an increase of capillary permeability at the site of application. Also, the inhibitory effects of anti-inflammatory agents (diphenhydramine, dexamethasone, indomethacin, cyproheptadine hydrochloride, CV3988 and AA-861) to PRL-induced erythema formation demonstrated that histamine and prostaglandins were responsible for the inflammatory reactions induced by PRL.

The short wavelength-sensitive cone electroretinogram in diabetes: relationship to systemic factors

The short wavelength-sensitive (S-) cone electroretinogram (ERG) is selectively reduced in diabetic patients both with and without retinopathy, but the exact mechanism of the vulnerability of the S-cone system is still unclear. This study examined relationships of the S-cone ERG to systemic factors in diabetes. Cone ERGs to different color flash stimuli were examined in the presence of bright white background illumination in 17 diabetic patients without retinopathy and in 17 diabetics with background retinopathy. Relationships of the amplitude and implicit time of the S-cone ERG to the following systemic factors were statistically analyzed: patients' age, hemoglobin A1 level, method of diabetic control, presence of retinopathy, and presence of nephropathy. The amplitude of the S-cone ERG b-wave was significantly reduced in diabetics treated with insulin and in those associated with nephropathy. No significant correlation was found between the S-cone ERG and patient's age, hemoglobin A1 level and presence or absence of retinopathy. A selective reduction of the S-cone ERG is observed in patients whose metabolic control has been poor for a longer period, suggesting that microvascular changes may play a role in the S-cone ERG impairment.

Steroid-responsive optic neuropathy in a patient with Tolosa-Hunt syndrome: electrophysiologic findings

We examined visual evoked potentials and pattern electroretinograms in a patient with Tolosa-Hunt syndrome associated with optic nerve involvement. The 82-year-old woman developed unilateral painful ophthalmoplegia and visual loss in the right eye. Magnetic resonance imaging showed an abnormal soft-tissue area in the right cavernous sinus and the right orbital apex. Symptoms responded rapidly to treatment with corticosteroid. Visual evoked potentials to flash and pattern stimuli were both remarkably reduced and delayed in the right eye in the acute stage; however they improved to almost normal after steroid therapy. The pattern electroretinogram recorded in the acute stage was normal bilaterally. These results indicate that optic nerve involvement in Tolosa-Hunt syndrome can be mild and reversible.

Human platelet Fc receptors: binding kinetics of Fc derivatives to the receptors

Human platelets are known to carry Fc receptors (Fc R), but the binding characteristics between ligands and Fc gamma R has not been well elucidated. In this study, we investigated the binding kinetics of IgG Fc fragments (Fc) to Fc R, the association and dissociation characteristics of the ligands to and from Fc gamma R using enzymatically modified Fc fragment derivatives. Approximately 60 minutes and 90 minutes were needed at 37 degrees C and 22 degrees C, respectively, for complete saturation of the Fc binding sites with horseradish peroxidase-conjugated Fc (HPO-Fc). Heat aggregated IgG (HAG) had a greater affinity for the Fc gamma R than Fc monomers. Additional binding of HAG was observed even after the binding sites were saturated with Fc monomers. This could be explained by different binding sites available only for immune complexes or by the partial dissociation of binding sites saturated with Fc by HAG. Further, we noted partial dissociation of HPO-Fc, when HAG was added after saturation of the binding sites with HPO-Fc. In a subsequent experiment, we compared the relative affinities of chemically or enzymatically modified Fc derivatives for Fc gamma R. HAG, which was used as a model for CIC, had a greater affinity for platelet Fc gamma R than IgG monomer and Fc derivatives. Pepsin-digestion of Fc caused a total loss of its affinity for the Fc gamma R, whereas b-mercaptoethanol-treated Fc fragments demonstrated substantial binding to the Fc gamma R. These results indicate that the pepsin digestion affects the Fc portion and causes a disruption in the area of the Fc which is essential for the recognition by the platelet Fc gamma R. On the other hand, cleavage of disulfide bridges by beta-mercaptoethanol resulted in a marked increase in affinity for the Fc gamma R. On the other hand, enzymatic cleavage of the carbohydrate moieties of Fc did not alter the affinity of Fc fragments for the Fc gamma R, indicating that the carbohydrates play an insignificant role or are not involved in their binding to the Fc gamma R.

A highly specific functional test for factor V leiden: A modified tissue factor assay for activated protein C resistance

We compared the sensitivity and specificity of a tissue factor-based assay (FVR) with the addition of a phospholipid/silica preparation, to the commercially available aPTT-based method, APCR (CoatestTM), and a modified aPTT-based method (APCM) which utilized factor V-depleted plasma, for the detection of the factor V Leiden mutation. A total of 110 patients were included in this study. This included 32 patients on coumadin therapy, 7 patients on heparin therapy, 5 patients on both anticoagulants therapy, and 24 patients who were positive for anticardiolipin antibody (ACL) and/or lupus inhibitor (LI). Our data demonstrate that the FVR is not affected by anticoagulation treatment or ACL/LI antibodies, whereas in the APCR method, 33 patients cannot be determined either due to the anticoagulant therapy or presence of the ACL and/or LI. With the APCM method, the clotting endpoint could not be determined in 1 patient due to the presence of a strong LI. The additional phospholipid/silica material utilized in the FVR enhanced the APC degradation of factor Va and therefore sharpened the demarcation between the factor V Leiden-positive and -negative patients. The sensitivity for the APCR, APCM and FVR was 42, 97 and 100% respectively. The specificity for the APCR, APCM and FVR was 94, 96 and 100% respectively.

Cone electroretinogram to chromatic stimuli in myopic eyes

The cone electroretinograms (ERGs) to different chromatic stimuli were recorded in myopic subjects. Ganzfeld color flashes under bright white background illumination were used to elicit short-wavelength-sensitive (S-), and mixed long-(L-) and middle-(M-) wavelength-sensitive cone ERGs. Nineteen subjects with mild myopia (between -3.0 and -6.0 D), 12 subjects with high myopia (greater than -6.25 D) but without chorioretinal atrophy or posterior staphyloma, and 22 age-matched normal controls were compared. The S-cone and L,M-cone b-wave amplitudes decreased progressively with increasing myopia. The amplitudes of the S-cone and the L,M-cone b-wave were significantly lower in highly myopic subjects, as compared with controls. The implicit times of both b-waves were normal in most myopic subjects. The S-cone and the L,M-cone ERGs were almost equally affected in myopic eyes. The selective reduction of the S-cone pathway in high myopia, reported previously, may not originate from the other retina.

Relationship between amount of beta-blockers permeating through the stratum corneum and skin irritation after application of beta-blocker adhesive patches to guinea pig skin

We evaluated the relationship between the cumulative amounts of 5 kinds of beta-blockers (alprenolol, oxprenolol, timolol, acebutolol and atenolol) permeating through the stratum corneum and a* values obtained by measuring the formation of erythema, a skin irritation reaction, with a chromameter after transdermal application of adhesive patches containing 2 beta-blocker to the skin of guinea pigs. The cumulative amount of beta-blocker released from each adhesive patch to the skin increased with the increase in application time. The contents of alprenolol, oxprenolol and timolol in the stratum corneum and in the stripped skin increased markedly up to 4 h after application and thereafter were maintained at high levels up to 24 h. The contents of acebutolol and atenolol, on the other hand, increased up to 24 h, but these values were low. a* values of all adhesive patches 24 h after application were higher than those before application. The correlation coefficients between the cumulative amounts of alprenolol, oxprenolol, timolol, acebutolol or atenolol permeating through the stratum corneum and (delta a* -delta a*Placebo) values were 0.739, 0.717, 0.722, 0.551 and 0.633, respectively. The correlation coefficient calculated by averaging the cumulative amounts of 6 kinds of beta-blockers permeating through the stratum corneum [including propranolol which was reported previously (Kobayashi I., et al., Biol. Pharm. Bull., 19, 839-844 (1996))] was 0.731, higher than the correlation coefficient between contents of these beta-blockers in the stripped skin and (delta a* -delta a*Placebo) values (r = 0.552). This suggests that there was a high correlation between the cumulative amounts of beta-blockers permeating through the stratum corneum and (delta a* -delta a*Placebo) values.

Right active retinitis and left focal retinochoroidal scar in a girl with congenital toxoplasmosis

In congenital cases, ocular toxoplasmosis often presents as a focal whitish fluffy lesion in the retina adjacent to an inactive chorioretinal scar. We examined a girl who has visible floaters in the right eye. The patient had focal active retinitis in the right fundus, a focal chorioretinal scar in the left fundus, a positive enzyme-linked immunosorbent assay (ELISA) for IgG anti-Toxoplasma antibodies and a negative ELISA for IgM antibodies. We believe that active focal retinitis in one eye and a focal chorioretinal scar in the fellow eye in congenital toxoplasmosis, as demonstrated in our patient, may be rare.

Selective reduction of the S cone electroretinogram in diabetes

AIMS

To determine whether the short wavelength sensitive (S) cone electroretinogram (ERG) is selectively altered in diabetic patients with and without retinopathy.

METHODS

Ganzfeld spectral flashes in the presence of bright white background illumination were used to elicit S cone ERGs is 15 non-retinopathic diabetics, 16 background retinopathic diabetics, and 16 age matched normal controls.

RESULTS

The amplitude of the S cone ERG b-wave was significantly reduced in both non-retinopathic and retinopathic diabetics. An action spectrum based on equal response criteria revealed a selective loss of S cone sensitivity in diabetics. However, no significant difference was observed in the long and middle wavelength sensitive cone ERG.

CONCLUSIONS

Diabetic patients showed selective reduction of the S cone ERG, which is thought to reflect changes in the outer retina.

Undetectable S cone electroretinogram b-wave in complete congenital stationary night blindness

AIMS

The short wavelength sensitive (S) cone electroretinograms (ERGs) were examined in two patients with the complete type of congenital stationary night blindness (CSNB).

METHODS

Ganzfeld spectral flashes in the presence of strong white adapting fields were used to elicit the S cone ERGs.

RESULTS

The S cone ERG b-wave was not detectable to short wavelength stimuli, while the mixed long (L) and middle (M) wavelength sensitive cone responses appeared normal in waveforms with normal amplitude in both patients. Both patients had normal colour vision on the Farnsworth Panel D-15.

CONCLUSIONS

These ERG results indicated that the S cone system as well as rod system is more impaired in complete CSNB than the L and M cone system and that normal colour vision may not depend on a normal S cone ERG to full field stimuli.