PO-16 - ASK1 regulates tumor lung metastasis and platelet functions

INTRODUCTION

Apoptosis signal-regulating kinase 1 (ASK1) is a MAP3K in the JNK and p38 MAPK pathways and responds to various stresses. Accumulating evidence indicates that ASK1 plays important roles in tumorigenesis by regulating apoptosis and inflammation. However, little is known about ASK1's roles in tumor metastasis.

AIM

To investigate ASK1's roles in tumor metastasis.

MATERIALS AND METHODS

We performed experimental lung metastasis model by intravenous injection of Lewis lung carcinoma cells constitutively expressing luciferase (3LL-Luc2 cells). As for the analysis of platelet functions, tail bleeding assay and ferric chloride-induced thrombosis model were utilized.

RESULTS

We measured the transition of luciferase activity of the lung lysates up to 7 days as an indicator of lung metastasis. ASK1-/- mice showed markedly lower luciferase activity as early as 3 hours after injection compared to WT mice; hence ASK1 appears to be involved in the early stage of tumor lung metastasis, which is prior to the extravasation of tumor cells. Platelets aggregate and adhere to tumor cells in the early stage and are known to support hematogenous metastasis. ASK1-/- mice were normal in hematological parameters including platelet number, while analysis by western blot revealed that platelets of ASK1-/- mice exhibited markedly reduced phosphorylation of JNK and p38, both of which have been reported to regulate platelet functions such as platelet aggregation. We found that platelets of ASK1-/- mice were less responsive to specific aggregation agonists and that ASK1-/- mice showed bleeding tendency and defect in thrombosis. These phenotypes were also observed in megakaryocyte and platelet-specific ASK1 deficient mice.

CONCLUSIONS

It is suggested that impaired platelet functions caused by ASK1 deficiency in platelets may attenuate tumor lung metastasis.

Postoperative chylothorax in congenital diaphragmatic hernia

INTRODUCTION

The mechanisms responsible for postoperative chylothorax in Congenital Diaphragmatic Hernia (CDH) patients remain unclear. The aim of the present study was to examine the clinical features of CDH that may contribute to an association with postoperative chylothorax.

MATERIAL AND METHODS

198 neonates with CDH, in whom surgical repair of a diaphragmatic defect was performed between 1981 and 2008, were retrospectively studied. The patients were divided into 2 groups; patients with postoperative chylothorax (group I, n=11) and patients without postoperative chylothorax (group II, n=187). The clinical findings were compared between group I and group II to investigate potential predictive parameters for an association with chylothorax. Moreover, the clinical findings and treatments were evaluated in patients with chylothorax.

RESULTS

11 of the 198 infants (5.5%) developed a chylothorax. Although the incidence of a prenatal diagnosis was slightly higher in group I, no relationship with other clinical features was found which would indicate the severity of CDH or the occurrence of postoperative chylothorax. Treatment for chylothorax was drainage alone in 2 cases, total parenteral nutrition with drainage in 8 infants and additional intrathoracic OK-432 infusion in 1 patient. No patients required surgical intervention for chylothorax. No recurrences were observed in this patient series.

CONCLUSIONS

It was concluded that postoperative chylothorax is not rare in infants after CDH repair. However, no statistically significant predictive parameters for chylothorax were identified, except for the presence of a prenatal diagnosis.

Efficacy and safety of torasemide in children with heart failure

OBJECTIVE

To examine the efficacy and safety of torasemide in children with chronic heart failure (HF).

METHODS

102 children with chronic HF who had received oral torasemide were analysed. Of these, 62 (de novo group) were newly diagnosed as having HF and were given torasemide as a diuretic. The remaining 40 (replacement group) had been given furosemide for >3 months before the study, and furosemide was then replaced with torasemide. Clinical signs and symptoms of HF (assessed as the HF index), humoral factors and serum potassium concentrations before torasemide treatment were compared with those obtained 3-4 weeks after torasemide treatment. Patients were also monitored for adverse effects.

RESULTS

In the de novo group, torasemide significantly improved the HF index with concomitant improvement in plasma brain natriuretic peptide concentration (median (interquartile range) 52 (51) vs 43 (49) pg/ml). In a randomly selected group of 25 de novo patients with ventricular septal defect, echocardiography showed that torasemide significantly improved left ventricular geometry and function. In the replacement group, brain natriuretic peptide concentrations were also significantly decreased from 50 (104) to 45 (71) pg/ml after substitution of torasemide, but the HF index showed only a tendency for improvement (p = 0.07). Torasemide also had a potassium-sparing effect (de novo group, no change in potassium concentration; replacement group, significant increase from 4.2 (0.5) to 4.3 (0.5) mEq/l), and caused a significant rise in serum aldosterone concentration, consistent with the anti-aldosterone effect of this drug. Serum concentrations of sodium and uric acid had not changed after torasemide treatment, and there were no serious adverse events that necessitated drug withdrawal.

CONCLUSION

Torasemide can be safely used, and appears to be effective for treatment of HF in children. Future clinical trials are warranted to verify the present results.

Computer-assisted linearization of the von Krogh Curve for the measurement of serum complement titre

Computer simulations of complement titre measurement in sera by linearizing the sigmoidal curve of complement dose response were performed, to simplify the logarithmic calculations of CH50 values. CH50 titres of large variety of human sera including healthy donors and immune deficiency patients were estimated. The values obtained were compared with the hand-simulated results using the Y/(1-Y) conversion table and a log-log graphic paper. Using computer simulation, CH50 can be determined with great ease.

EP2, a receptor for PGE2, regulates tumor angiogenesis through direct effects on endothelial cell motility and survival

Prostaglandin E2 (PGE2), a major cyclooxygenase (COX) metabolite, plays important roles in tumor biology. We studied the role of EP2, a receptor for PGE2, in tumor angiogenesis using EP2 knockout mice. We found that deletion of the EP2 receptor impaired tumor angiogenesis and this finding was confirmed by an in vivo corneal angiogenesis model and an ex vivo aortic ring assay. To further characterize the cellular mechanisms of the EP2 receptor in angiogenesis, we isolated primary pulmonary endothelial cells (ECs) from wild-type (wt) and EP2-/- mice and observed that EP2-/- ECs exhibited defects in vascular branch formation when compared to wt ECs. In addition, EP2-/- ECs showed impaired cell motility on collagen-coated surface and they responded poorly to PGE2-induced cell migration compared to control cells. However, no difference in cell proliferation was observed between the EP2-/- and wt Ecs. In addition, EP2-/- ECs were more susceptible to apoptosis than wt cells under growth factor depletion conditions. Collectively, our data demonstrate that EP2 signaling in endothelium directly regulates tumor angiogenesis by contributing to cell survival and endothelial cell motility. Moreover, our finding suggests that EP2 is a major receptor in PGE2-mediated cell motility in ECs.

Moderate increase of mean daily temperature adversely affects fruit set of Lycopersicon esculentum by disrupting specific physiological processes in male reproductive development

BACKGROUND AND AIMS

Global warming is gaining significance as a threat to natural and managed ecosystems since temperature is one of the major environmental factors affecting plant productivity. Hence, the effects of moderate temperature increase on the growth and development of the tomato plant (Lycopersicon esculentum) were investigated.

METHODS

Plants were grown at 32/26 degrees C as a moderately elevated temperature stress (METS) treatment or at 28/22 degrees C (day/night temperatures) as a control with natural light conditions. Vegetative growth and reproductive development as well as sugar content and metabolism, proline content and translocation in the androecium were investigated.

KEY RESULTS

METS did not cause a significant change in biomass, the number of flowers, or the number of pollen grains produced, but there was a significant decrease in the number of fruit set, pollen viability and the number of pollen grains released. Glucose and fructose contents in the androecium (i.e. all stamens from one flower) were generally higher in the control than METS, but sucrose was higher in METS. Coincidently, the mRNA transcript abundance of acid invertase in the androecium was decreased by METS. Proline contents in the androecium were almost the same in the control and METS, while the mRNA transcript level of proline transporter 1, which expresses specifically at the surface of microspores, was significantly decreased by METS.

CONCLUSIONS

The research indicated that failure of tomato fruit set under a moderately increased temperature above optimal is due to the disruption of sugar metabolism and proline translocation during the narrow window of male reproductive development.

Gene and protein expression profiles of prostaglandin E2 receptor subtypes in the human corpus cavernosum

Prostaglandin E1 leads to penile erection, mainly via prostaglandin E2 (EP) receptors. This study aimed to identify the expression profile of EP receptor genes in human corpus cavernosum. Using the quantitative real-time reverse transcription polymerase chain reaction, the mRNA levels of EP receptor subtypes were measured. In addition, expressions of EP receptor subtype proteins were determined by immunohistochemical method. Among the four subtypes, EP4 receptor mRNA expression was the highest, and EP2 receptor mRNA followed, whereas EP1 and EP3 receptor mRNAs were hardly observed. Expression level of EP4 receptor mRNA was significantly higher than that of EP2 receptor mRNA. Expression of both EP2 and EP4 receptor proteins were clearly detected in the cavernous smooth muscle. These results may suggest that EP4 receptor plays an important role among four EP receptor subtypes for relaxation of smooth muscle in the human corpus cavernosum.

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.

Relationship between the amount of propranolol permeating through the stratum corneum of guinea pig skin after application of propranolol adhesive patches and skin irritation

In the present study we evaluated the relationship between the cumulative amount of propranolol permeating through the stratum corneum and the formation of erythema, a skin irritation reaction, after transdermal application of adhesive patches containing propranolol to the skin of guinea pigs. The intensity of erythema was expressed in terms of a* values measured with a chromameter. The a* values increased in guinea pigs after application of the adhesive patches containing 0.4 mg/cm2 of propranolol to the skin. Since the adhesive patches showed good adhesion to the skin (propranolol content is less than the saturated concentration in the adhesive base) and the cumulative amount of propranolol permeating through the stratum corneum is small, the development of erythema was considered to be mainly due to physical factors such as peeling. Even in adhesive patches containing 0.8 mg/cm2 or 1.2 mg/cm2 of propranolol, a* values increased, although adhesion to the skin is low because of crystallization of propranolol in the adhesive base. On the other hand, in these two adhesive patches, the cumulative amount of propranolol permeating through the stratum corneum increased up to 24 h after application. These findings suggest that the skin irritation reaction is due to propranolol mainly absorbed transdermally, because there is a high correlation between the cumulative amount of propranolol permeating through the stratum corneum and the a* values (r = 0.928).

Menstrual stage influences postoperative nausea and vomiting following epidural buprenorphine

BACKGROUND

Although buprenorphine sometimes causes severe emesis, its relation to the menstrual cycle has not been reported.

METHODS

We conducted a prospective study on 68 reproductive-age women following lower extremity surgery under epidural anesthesia plus buprenorphine, to assess the effect of the day of the menstrual cycle on the incidence of postoperative nausea and vomiting. The patients were divided according to the phase of the menstrual cycle into four groups: day 1-7 group, day 8-14 group, day 15-24 group and day 25 to end of the cycle group.

RESULTS

Nausea and vomiting were reported in 46 patients (67.6%), and the incidence was higher in the day 25 to end of the cycle group than in the day 8-14 or day 15-24 groups, and higher in the day 1-7 group than in the day 8-14 group.

CONCLUSION

We conclude that emesis after epidural buprenorphine is related to the menstrual cycle.

[The clinical usefulness and problem of combined spinal epidural needle]

The clinical usefulness of combined spinal-epidural needles, Portex Spinal/Epidural set (Pencil point tip type and Lancet point tip type), was evaluated on 30 patients undergoing orthopedic lower limb surgeries, hysterectomies or transurethral surgeries. In all the patients, the spinal-epidural needles were successfully inserted with paramedian approach without any problem. The time to appearance of cerebrospinal fluid in the spinal needle hub after removal of the stylet was 15-40 seconds, and no patient in both groups had postspinal headache. Following spinal anesthesia, the local anesthetics injected through the epidural catheter extended the analgesia in the range of 1-2 dermatomes higher in the Lancet point type group in comparison with Pencil point type group. It is possible that the hole in the dura may allow a transfer of local anesthetics into the subarachnoid space. The present study shows that combined spinal-epidural block is clinically useful, and the Pencil point type is safer than the Lancet point type.

Nondetectable S-cone electroretinogram in a patient with crystalline retinopathy

We examined cone and rod electroretinograms to ganzfeld stimuli in a patient with crystalline retinopathy. The 54-year-old man complained of night blindness, blurred vision, and metamorphopsia in both eyes. His visual acuity was 10/200 in the right eye and 10/20 in the left eye; his subjective dark-adaptation threshold was elevated 1 log unit, and he made one tritan error on the Farnsworth Panel D-15. Specular microscopic examinations revealed tiny crystalline deposits in the limbal cornea bilaterally. Ophthalmoscopically, crystalline deposits were found in the posterior fundi. His light-adapted cone electroretinograms to white stimuli were diminished (about 30% of those of normal controls), with normal implicit times. His dark-adapted rod electroretinogram amplitudes were 10% of those of normal controls. The S-cone electroretinogram was not detectable to different spectral stimuli with strong white background, while the L-M-cone responses appeared normal in waveforms with reduced amplitude. These ERG results indicated that the patient's S-cone system is more highly impaired than the L-M-cone system, supporting the psychophysical evidence that the S-cone system is more vulnerable than other cone systems in retinal diseases.

Characterization of human platelet IgG Fc receptor associated with membrane glycoprotein

Human platelets express IgG Fc receptors (Fc gamma R). Previously we reported that circulating immune complexes (CIC) inhibited fibrinogen binding to platelet glycoprotein IIb/IIIa complex (GPIIb/IIIa) and that isolated Fc gamma R were recognized by monoclonal antibodies (mAb's) to GPIIb and GPIIIa (J.Lab. Clin. Med. 117:209-217, 1991). In this study, we further characterized the properties of the Fc gamma R and the activity associated with GPIIb/IIIa. Binding of Fc portion of human IgG (Fc) to the platelet Fc gamma R associated with GPIIb/IIIa complex, unlike fibrinogen receptor, did not require divalent cations. The Fc gamma R bound to immobilized immune complex were recognized by mAb's to GPIIb, GPIIIa, GPIIb/IIIa. Preincubation of platelet extract with fibrinogen inhibited the binding of heat-aggregated IgG (HAG) to the extract. Flow cytometry of whole platelets revealed inhibition of mAb binding to GPIIb/IIIa, when platelets were incubated with Fc fragments or HAG. Using platelet extract coated to microtiter plates, similar findings were noted with Fc and HAG. The dissociation of GPIIb/IIIa complex by incubating platelet extract at 37 degrees C in the presence of EDTA caused a marked decrease in the binding of GPIIb and GPIIIa to the immobilized immune complex. Activation of intact platelets with ADP resulted in an increased binding of HAG to the platelets, indicating that an augmented Fc gamma R activity is associated with the activation of GPIIb/IIIa. These results suggest a close relationship of the Fc gamma R activity to the fibrinogen binding site (GPIIb/IIIa complex).

Acquired von Willebrand's syndrome in association with a lupus-like anticoagulant corrected by intravenous immunoglobulin

We are reporting on a 47-year-old man who presented with a prolongation of the activated partial thromboplastin time (APTT) prior to orthopedic surgery. An evaluation suggested an inhibitor when his plasma prolonged a normal control APTT upon 50:50 solution of patients with normal plasma. The platelet-neutralizing procedure (PNP), anticardiolipin antibody, and antinuclear antibody (ANA) were positive. Further studies revealed decreased von Willebrand factor ristocetin cofactor (vWF:RCoF), von Willebrand factor antigen (vWF:Ag), an inhibitor to vWF, and absent high-molecular-weight vWF multimeters. Assays of FVIII:C, FIX, and FXI were nonparallel to the standard curve. Intravenous immunoglobulin (IVIG) corrected the APTT, multimeric pattern, and FVIII:C by the 7th day postinfusion. This case demonstrates the efficacy of IVIG for acquired von Willebrand's syndrome (vWS) and also represents a unique combination of a lupus-like anticoagulant and acquired vWS in a patient without the full serological requirement for systemic lupus erythematosus (SLE). Whether patients with acquired vWS and lupus inhibitors are more or less susceptible to either a thrombotic complication or hemorrhage is not established. Prospective studies for the incidence of lupus inhibitor/antiphospholipid syndromes and vWF deficiencies are needed to assess this question.

Host factors required for internal initiation of translation on poliovirus RNA

Translation of poliovirus RNA is initiated by entry of ribosomes into the nucleotide sequence (internal ribosomal entry site; IRES) within the 5'-untranslated region (5'-UTR). Efficiency of this translation initiation in rabbit reticulocyte lysates (RRL) was very low and was greatly enhanced by addition of the ribosomal salt-wash fraction (RSW) prepared from HeLa cells. This stimulating activity in the RSW was partially purified by gel-filtration column chromatography and its molecular weight was estimated to be higher than 240,000. Several proteins that bind specifically to the poliovirus IRES were detected in the active fraction. Among those, a 57 kDa protein, recognized by antibodies against polypyrimidide tract-binding protein (PTB), was found. In addition, La protein (52 kDa) which is a human antigen recognized by antibodies from patients with autoimmune disorders was also detected. Further purification on a hydroxylapatite column resulted in considerable loss of the stimulatory activity, accompanied by a reduction of the apparent molecular weight of active component(s). These results suggest that fully active HeLa cell stimulatory factors for the translation initiation on poliovirus RNA function in RRL as a large complex consisted of several components including PTB and La protein.

Effect of intravenous immunoglobulin on inhibition of fibrinogen binding to platelets by sera from patients with immune thrombocytopenia

We previously described an ELISA to measure the inhibition of platelet glycoprotein IIb/IIIa (GPIIb/IIIa) binding to fibrinogen due to immune complexes and/or anti-platelet antibodies from patients with immune thrombocytopenia (ITP) or HIV-related ITP. Circulating immune complexes (CIC) were the main factor in the inhibition of GPIIb/IIIa binding to fibrinogen in HIV-related ITP, whereas in non-HIV ITP, inhibition was only partially due to CIC; anti-platelet antibodies specific to GPIIIa were also shown to play a role. In this study, we correlated the rise in the platelet count after intravenous immunoglobulin (IVIG) infusion with the decrease in inhibition of fibrinogen binding to GPIIb/IIIa by the sera of patients with ITP and HIV-related ITP. In the majority of the patients' sera tested, as the platelet count increased following the administration of IVIG, the degree of inhibition of GPIIb/IIIa binding to fibrinogen decreased. We also observed a decrease and/or disappearance of the antibodies specific to GPIIb and/or GPIIIa after IVIG administration. In HIV-seronegative ITP patients, the decrease or disappearance of anti-platelet antibodies directly correlated with the decreased inhibition of GPIIb/IIIa binding to fibrinogen by the 2% PEG supernatants of sera which contained anti-platelet antibodies. These findings suggest that IVIG directly affects the binding of CIC and anti-platelet antibodies to platelets and thereby improves platelet survival. Our results also suggest that the anti-idiotypic effect may contribute to IVIG's therapeutic action. In contrast, in the HIV-seropositive group, the decreased inhibition by PEG precipitates after IVIG administration was more strongly associated with an increase in the platelet count.

Dysfunctional platelet glycoprotein IIb/IIIa associated with a platelet release defect: a family study

We are reporting on a 36-year-old white female with a bleeding history attributed to dysfunctional platelet glycoprotein IIb/IIIa (GPIIb/IIIa) and a coexisting platelet release defect. Platelet aggregation studies (PAS) revealed markedly diminished to absent responses to ADP, epinephrine, collagen and arachidonic acid; the ristocetin response was normal. ATP content was normal with poor release to the agonists as measured by luminescent technique. DDAVP infusion shortened bleeding time from 13.5 min to 8.0 and 12 min (at 1 and 2 hours). Flow cytometry and immunoblotting revealed normal amounts of GPIIb and diminished GPIIIa (50% of control). Using a previously reported ELISA which measures the binding of GPIIb/IIIa to immobilized fibrinogen, the patient's platelet extract showed no binding to fibrinogen. Both the father and mother were found to have decreased PAS responses and normal amounts of GPIIb/IIIa determined by both Western blot and flow cytometry. However, the ELISA showed decreased binding of their GPIIb/IIIa to fibrinogen (71% and 62% as compared to controls, respectively). The patient's dysfunctional fibrinogen receptor was clearly demonstrated by the ELISA. The parents had moderately reduced GPIIb/IIIa function in this assay, but they did not demonstrate a reduced GPIIIa as was noted in the patient. The parents' PAS indicated a platelet release defect. These findings suggest an inherited platelet release defect and a dysfunctional GPIIIa. The partial response to DDAVP would be compatible with the presence of a platelet release defect.

Inhibition of human platelet glycoprotein IIB/IIIA binding to fibrinogen by tumor cell membrane proteins

Immunochemical and functional characteristics of tumor cell membrane proteins and human platelet glycoproteins were studied. Immunoblotting revealed that membrane proteins of a cultured breast tumor cell line (BT-20) had three protein bands, which were each recognized by monoclonal antibodies to human platelet glycoprotein Ib, IIb, and IIIa, suggesting some immunochemical similarities between the tumor cell membrane proteins and platelet glycoproteins. The monoclonal antibodies failed to bind to an extract of a lung tumor cell line (A549). Neither tumor extract induced platelet aggregation. However, tumor-associated antigens isolated from the breast tumor cells markedly inhibited platelet glycoprotein IIb/IIIa binding to fibrinogen. In contrast, tumor-associated antigens from the lung tumor cells had no effect. These results suggest that tumor cells which have immunological and/or structural similarities to platelets may affect hemostasis and coagulation in vivo.