A simple assay system for examination of the inhibitory potential in vivo of decoy RNAs, ribozymes and other drugs by measuring the Tat-mediated transcription of a fusion gene composed of the long terminal repeat of HIV-1 and a gene for luciferase

Nucleic acid-based drugs, including antisense RNA and DNA, ribozymes and decoys appear to have potential for the suppression of the expression of specific genes. To allow the examination of the potential of such agents in vivo as anti-HIV drugs in standard laboratories, where facilities for handling live virions are not available, we constructed a simple assay system (HIV-1 model) that allows measurement of the extent of inhibition of Tat-mediated transcription of HIV-1 by nucleic acid-based drugs and other agents. In cells that harbor a stable chimeric long terminal repeat (LTR)-Luc construct (a fusion gene consisting of the LTR of HIV-1 and the gene for luciferase), total luciferase activity in an aliquot of cell lysate is dose- and promoter-dependent on transfection with a Tat expression plasmid, reflecting the character of the LTR promoter of HIV. When HeLa cells were co-transfected with the Tat expression plasmid and another plasmid that encoded the U6 promoter or the promoter of the gene for tRNA(Val) linked to the trans-activating response (TAR) sequence, total luciferase activity was inhibited by 60 or 40%, respectively. The inhibition was also dependent on the dose of the TAR expression plasmid. These results demonstrate the usefulness of this simple assay system for detection of the efficacy of a decoy RNA or a ribozyme in vivo, without a requirement for HIV-infected cells, by measurement of luciferase activity in vitro.

Idiopathic mediastinal fibrosis: report of a case

We report herein the case of a 28-year-old woman who presented with a mediastinal mass, subsequently confirmed to be idiopathic mediastinal fibrosis. Preoperative chest computed tomography (CT) showed a noncalcified mediastinal mass and surgery was performed to exclude malignancy. The mass was hard and dense, involved the left phrenic nerve, vagus nerve, and left upper lobe, and surrounded the subclavian artery, subclavian vein, superior vena cava, and left pulmonary artery. Pathologic examination showed the findings of mediastinal fibrosis and the mass was partially excised. Postoperative medical treatment was performed with prednisolone and tranilast, and a 3-year follow-up has not demonstrated any complications.

Bcl-2 expression and prognosis of patients with endometrial carcinoma

Bcl-2 protein inhibits apoptosis, reduces the requirement for growth factors, and thereby extends the survival of cells. Recent findings of Bcl-2 in several solid tumors suggest that it might contribute to the genesis of some types of cancer. Over-expression of Bcl-2 might play a role in carcinogenesis and malignant progression of endometrial carcinoma. The aims of this study were to determine Bcl-2 expression in endometrial carcinoma in relation to other histopathologic prognostic factors, and to test its prognostic significance in patients with endometrial carcinoma. A total of 61 endometrioid-type endometrial carcinomas were immunohistochemically investigated for Bcl-2 expression on cryostat sections. Bcl-2 localization was observed in cytoplasm in 18 tumors, in nucleus in 27 tumors, or in both in 5 tumors. In 11 tumors, Bcl-2 was observed neither in cytoplasm nor in nucleus. There was not a statistically significant relationship between grade of tumor and Bcl-2 expression. Cytoplasmic Bcl-2 became less frequently expressed as the tumor invaded the myometrium deeper (p < 0.025). Retroperitoneal lymph-node dissection was performed in 57 patients. Multiple-regression analysis showed that lymph-vascular space invasion and nuclear expression of Bcl-2 were correlated to pelvic lymph-node metastasis (p < 0.0001 and < 0.05 respectively). Univariate Cox regression analysis revealed that nuclear Bcl-2 expression was associated with shorter survival (p < 0.05) than that of patients with cytoplasmic Bcl-2 expression. Pelvic node metastasis was a significant prognostic factor for patients who underwent systematic retroperitoneal lymph-node dissection. Cox multivariate-regression analysis revealed that pelvic node metastasis and cervical invasion were the most important prognostic factors in this series of patients. When the analysis was made after exclusion of pelvic node metastasis, histologic grade (hazard ratio = 2.4), cervical invasion (hazard ratio = 3.7) and nuclear Bcl-2 expression (hazard ratio = 11.5) were shown to be significant predictors of survival of the patients. These results indicate that aberrant Bcl-2 expression might be involved in malignant progression of endometrioid-type endometrial carcinoma. Site of Bcl-2 localization may be an important predictor of prognosis for patients with endometrioid-type endometrial carcinoma.

Structural basis for the electron transfer across the chromaffin vesicle membranes catalyzed by cytochrome b561: analyses of cDNA nucleotide sequences and visible absorption spectra

We isolated cDNA clones for cytochromes b561 from sheep and porcine adrenal medullae using the RT-PCR technique. Comparison of the deduced amino acid sequences of various species showed that there are two fully-conserved regions in this cytochrome. In addition, one methionyl and six histidyl residues (potential heme ligands) are fully-conserved. Based on a plausible structural model in which a polypeptide spans the vesicle membranes six times and holds two heme B molecules, the first conserved sequence (69ALLVYRVFR77) is located on the extravesicular side of an alpha-helical segment and the second one (120SLHSW124) is located in an intravesicular loop connecting two alpha-helical segments, respectively. Consideration of the relative locations of the fully-conserved sequences, and the methionyl and histidyl residues in the model led to a proposal that the first and second conserved sequences are likely to form the binding sites for extravesicular ascorbic acid and intravesicular semidehydroascorbic acid, respectively. A mild alkaline-treatment of purified bovine cytochrome b561 in oxidized state led to a specific loss of an electron-accepting ability from ascorbic acid for a half of the heme center, suggesting a distinct role for each of the two hemes.

Cerebral blood volume in the sleep measured by near-infrared spectroscopy

We investigated the relationship between hemodynamic changes in the cortex measured by near-infrared spectroscopy (NIRS) and the polysomnographic changes during sleep. Four healthy male volunteers participated in the study. Near-infrared spectroscopy measuring and polysomnographic recordings were done simultaneously during sleep. In many case, oxy-hemoglobin (oxy-Hb) decreased and deoxy-hemoglobin (deoxy-Hb) increased during the transition from wakefulness to sleep, and oxy-Hb increased toward deep sleep. Oxy-Hb and deoxy-Hb had larger fluctuations during REM sleep than those during non-REM sleep. During REM sleep, oxy-Hb often showed a lower level and deoxy-Hb showed a higher level than those during the preceding and following non-REM sleep.

Inhibition of experimental gastric carcinogenesis, induced by N-methyl-N'-nitro-N-nitrosoguanidine in rats, by sodium nitroprusside, a nitric oxide generator

The effects of prolonged administration of sodium nitroprusside (SNP), a generator of nitric oxide (NO), on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and the labelling index of the gastric mucosa were investigated in male Wistar rats. The rats received intra-peritoneal injections of 2 or 4 mg/kg body weight of SNP every other day after 25 weeks' oral treatment with the carcinogen. Prolonged administration of SNP at 4 mg/kg body weight, but not at 2 mg/kg body weight, significantly decreased the incidence of gastric cancers in experimental week 52. However, it did not affect the histological types or depths of involvement of gastric cancers. SNP at 4 mg/kg body weight, but not at 2 mg/kg body weight, also significantly decreased the bromodeoxyuridine labelling index of the antral epithelial cells. These findings indicate that SNP inhibits gastric carcinogenesis and suggest that this effect may be related to the suppression of proliferation of the antral epithelial cells.

Factor G pathway reactive activity (GPRA) after surgery for abdominal aortic aneurysm

BACKGROUND

Following major surgery, detection of endotoxaemia using the Toxicolor (Limulus) test has been reported. In addition to endotoxins, this test detects a reactant from human tissue, factor G pathway reactive activity (GPRA). We measured endotoxin and GPRA in 10 patients during and after elective surgery for abdominal aortic aneurysm. Additionally, we measured phosphokinase (CPK) and GPRA levels in the muscle of 10 patients during abdominal aortic aneurysm surgery and 6 during open laparotomy for other causes.

METHODS

Samples were taken from the arterial lines prior to surgery, before cross-clamping of the aorta, immediately after and 1, 3, 6, and 18 hours after declamping. Muscle specimens were taken from the rectus abdominus and homogenized in many levels. Endotoxin concentrations were measured with the Endotoxin-Specific test. GPRA concentrations were determined by subtracting the values from the Endotoxin-Specific test from those given by the Toxicolor test (Limulus assay with achromogenic substrate). CPK was also measured.

RESULTS

Endotoxin did not significantly increase during or after surgery, but GPRA was elevated. GPRA in muscle correlated significantly with CPK in muscle.

CONCLUSIONS

We conclude that GPRA was elevated after surgery, while endotoxin did not increase significantly. The GPRA probably originated from human muscle tissue.

Contracture of the deltoid muscle. Results of distal release

We prospectively studied the results of distal release, performed between February 1989 and December 1994 for the treatment of a contracture of the deltoid muscle, in forty patients (forty-nine shoulders). Forty-seven contractures (in thirty-eight patients) developed after multiple intramuscular injections of various medications. The two remaining contractures (in two patients) were congenital. The average age at the onset of the symptoms was thirty-two years (range, birth to fifty-eight years). The primary symptoms included pain around the neck and the shoulder girdle, dimpling of the skin, a palpable fibrous band, winging of the scapula, difficulty in combing the hair or reaching the contralateral side of the body for grooming, and inability to bring the arm adjacent to the body. The average age at the time of the operation was thirty-nine years (range, fifteen to sixty-three years). The average duration of follow-up was three years and eleven months (range, two years to six years and six months). After the distal release of the contracture, but on the same day, the patients started a physical-therapy program. Postoperatively, the pain, dimpling of the skin, palpable fibrous band, and winging of the scapula resolved in forty-eight shoulders (thirty-nine patients). Six patients (six shoulders) no longer had difficulty in combing the hair or adducting the shoulder. There were no infections or neuromuscular complications. Forty-seven (96 per cent) of the forty-nine shoulders (thirty-eight of the forty patients) had a good clinical result, and two shoulders (two patients) had a poor result. Anterosuperior subluxation of the humeral head, noted on preoperative radiographs of twenty-three shoulders (eighteen patients), was not present postoperatively. Drooping of the acromion, seen in six patients (six shoulders) in whom the contracture had developed before they were sixteen years old, improved postoperatively in five shoulders (five patients). Rotation of the scapula, seen in five shoulders (five patients), resolved after release of the contracture in all five. There were no clinical or radiographic signs of osteoarthrosis due to long-term anterior translation of the shoulder joint in the four patients (six shoulders) who had had the contracture for at least twenty years (average, twenty-three years; maximum, twenty-seven years).

Suppression by pravastatin, an inhibitor of p21ras isoprenylation, of hepatocarcinogenesis induced by N-nitrosomorpholine in Sprague-Dawley rats

The effect of pravastatin, an inhibitor of p21ras isoprenylation, on hepatocarcinogenesis induced by N-nitrosomorpholine and on p21ras isoprenylation were investigated in male Sprague-Dawley rats. Rats received i.p. injections of pravastatin (10 and 20 mg kg(-1) body weight) every other day and, from the beginning of the experiment, were given drinking water containing N-nitrosomorpholine for 8 weeks. Visible white nodules and hepatic lesions staining positively for gamma-glutamyl transpeptidase or glutathione-S-transferase, placental type, were examined macroscopically or histochemically. In week 15, pravastatin at both dosages significantly reduced the incidence, number and volume of visible white nodules. Quantitative histological analysis also showed that prolonged administration of pravastatin at both dosages resulted in significant reductions in the number and percentage area of hepatic lesions positive for gamma-glutamyl transpeptidase and glutathione-S-transferase, placental type. Administration of pravastatin also significantly decreased the amount of membrane-associated p21ras in the tumour and the labelling index of neoplastic nodules and increased the apoptoic indices of neoplastic nodules. These findings indicate that pravastatin suppresses hepatocarcinogenesis and suggest that this effect might be related to pravastatin's inhibition of p21ras isoprenylation and its subsequent inhibition of cell proliferation and induction of apoptosis in neoplastic lesions.

Receptors for natriuretic peptides in adrenal chromaffin cells

Atrial, brain, and C-type natriuretic peptides of the atrial natriuretic peptide family are present in adrenal chromaffin cells, and are secreted with catecholamines by exocytosis. These peptides modulate the physiological functions of the cells such as synthesis and secretion of catecholamines in an autocrine manner interacting with natriuretic peptide receptors.

Valve repair with chordal replacement for traumatic tricuspid regurgitation

A 70-year-old woman who had fatiguability due to right heart failure seven years after receiving blunt chest trauma in a road traffic accident presented to our hospital. Preoperative echocardiography revealed severe tricuspid regurgitation resulting from prolapse of the anterior leaflet. The valve was repaired by chordal replacement with expanded polytetrafluoroethylene sutures and DeVega annuloplasty. At three months after surgery, the patient is in good clinical condition, and repeat echocardiography revealed only mild tricuspid regurgitation.

Lectin affinity electrophoresis in a yolk sac tumour in the vagina with yolk sac tumour-type glycoform of alpha fetoprotein

AIMS

To investigate a potential diagnostic use of alpha fetoprotein (alpha FP) isoform analysis by lectin affinity electrophoresis to distinguish between endodermal sinus tumours arising in the vagina in infants from those at other sites.

METHODS

alpha FP in the serum of a patient with a vaginal endodermal sinus tumour was analysed for its isoforms by lectin affinity electrophoresis. The isoforms were compared with that of cord serum, sera of hepatoid adenocarcinoma of the uterus, and endodermal sinus tumour of the ovary.

RESULTS

The isoforms of alpha FP obtained by lectin affinity electrophoresis in the serum of the patient with vaginal endodermal sinus tumour differed from the isoforms of alpha FP in the cord serum of normal neonates, and sera of patients with hepatoid adenocarcinoma of the uterus or endodermal sinus tumour of the ovary.

CONCLUSIONS

Endodermal sinus tumour arising in the vagina could be distinguished from that in the ovary by the lectin affinity electrophoresis, and a potential diagnostic use of alpha FP isoform analysis by the lectin affinity electrophoresis for the detection of the endodermal sinus tumour in infants was demonstrated.

Three vha genes encode proteolipids of Caenorhabditis elegans vacuolar-type ATPase. Gene structures and preferential expression in an H-shaped excretory cell and rectal cells

The proteolipids of the vacuolar-type H+-ATPase (V-ATPase) are major components of the integral membrane sector. The vha-1 and vha-2 (vacuolar-type H+-ATPase) genes in Caenorhabditis elegans encode putative 16-kDa proteolipids and are tandemly localized on chromosome III. The vha-2 gene has three exons, whereas vha-1 has no introns. The deduced amino acid sequences of the two genes exhibit about 60% identity with the homologues from yeast, mouse, and cow. The mRNAs of both vha genes are trans-spliced to spliced leaders, suggesting that these genes constitute a polycistronic transcriptional unit. The vha-4 gene consists of four exons and is very similar to the yeast VMA16 gene that codes for the 23-kDa proteolipid. This is the first example of three distinct V-ATPase proteolipids being identified in higher eukaryotes. Northern blot and transgenic analyses show that the three vha genes may be highly expressed in the H-shaped excretory cell, rectum, and a pair of cells posterior to the anus. These results suggest that the V-ATPase activity may be important for exporting toxic compounds or metabolic wastes in this organism.

Ha-ras mutations in N-nitrosomorpholine-induced lesions and inhibition of hepatocarcinogenesis by antisense sequences in rat liver

To evaluate the application of Ha-ras mRNA antisense oligonucleotide therapy for liver tumors, we examined the frequency and types of mutation in codon 61 of the Ha-ras oncogene in preneoplastic lesions and hepatocellular carcinomas induced by N-nitrosomorpholine (NNM) in rats. Thirty-seven percent of preneoplastic lesions and 50% of hepatocellular carcinomas contained mutations, mostly CAA-CTA and CAA-AAA transversions. We also investigated the effects on NNM-induced lesions of an antisense oligonucleotide directed against a point mutation (CAA-CTA) in codon 61 of Ha-ras mRNA. In this experiment, Sprague-Dawley rats were given free access to water containing NNM for 8 weeks and received twice-weekly i.p. injections of a mutated Ha-ras antisense oligonucleotide with a 5' phosphorothioate linkage or a sense oligonucleotide in oligonucleotide-liposome complexes. At week 16, rats that had received the mutated Ha-ras antisense oligonucleotides had significantly fewer and smaller preneoplastic lesions positive for glutathione-S-transferase, placental type, and had smaller hepatocellular carcinomas than rats that had received the sense oligonucleotide. Mean cellular fluorescence in the liver was found to increase with higher doses of mutated, fluorescein-isothiocyanate-labeled antisense or sense oligonucleotides. Moreover, mutated Ha-ras antisense oligonucleotide decreased the expression of mutated Ha-ras mRNA (CAA-CTA). Our findings indicate that mutated Ha-ras antisense oligonucleotide significantly inhibits hepatocarcinogenesis in rats and could be an effective therapy against liver tumors.

Inhibition of transcription by the TAR RNA of HIV-1 in a nuclear extract of HeLa cells

Regulation of transcription of human immunodeficiency virus type-1 (HIV-1) requires specific interaction of Tat protein with the trans-activation response region (TAR). Inhibition of replication of HIV-1 has previously been achieved with a TAR decoy, namely a short RNA oligonucleotide that corresponded to the sequence of the authentic TAR RNA. Since TAR RNA has the potential to interact with cellular factors, we examined the effect of TAR RNA on efficiency of transcription in nuclear of HeLa cell extracts. We performed an in vitro transcription assay in the presence of authentic TAR RNA using a template that was driven by the CMV (cytomegalovirus) early promoter in a HeLa nuclear extract and found, for the first time, that TAR RNA inhibited transcription by approximately 60-70% independently of the Tat-TAR interaction. Furthermore, we evaluated inhibition of transcription by variants of TAR RNA and found that the TAR RNA loop, bases surrounding the loop, the triple base bulge and the 'lower' stem region of TAR RNA were responsible for the inhibition of transcription. Taken together, earlier reports on proteins that bind to TAR RNA and the present results suggest that integrity of TAR RNA is important for efficient binding to cellular transcription factors. As judged from the significant inhibition observed in this study, the TAR decoy might sequester transcription factors and thus it might potentially be able to inhibit transcription of housekeeping genes that are unrelated to Tat function.

Different responsiveness to nitric oxide-cyclic guanosine monophosphate pathway in cholinergic and tachykinergic contractions of the rabbit iris sphincter muscle

PURPOSE

In the rabbit iris sphincter muscle, sodium nitroprusside (SNP), a nitric oxide (NO) donor, inhibits cholinergic contraction but does not affect tachykinergic contraction in vitro. The objectives of the current study were to clarify the mechanism for the different responsiveness to NO in cholinergic and tachykinergic muscular contractions, and to examine whether the mechanism for NO-induced inhibition of cholinergic muscular contraction is operative in vivo.

METHODS

Iris sphincter muscle was dissected from the rabbit eye pretreated with or without endotoxin (lipopolysaccharide, LPS) in vivo. Cyclic guanosine monophosphate (cGMP) content in the iris sphincter muscle was determined by radioimmunoassay. The motor activity of the ring-shaped iris sphincter muscle was measured isometrically. Sodium nitroprusside, carboxy-2-phenyl-4,4,5,5,-tetramethyl-imidazoline-1-oxyl-3-oxide (C-PTIO, a scavenger of NO radicals), and 8-bromo cGMP (a permeable cGMP analogue) were administered between the first and second administrations of carbachol and neurokinin A, both of which had caused sustained contraction in the iris sphincter muscle.

RESULTS

Sodium nitroprusside inhibited the contraction of the iris sphincter muscle caused by carbachol but had no effect on the contraction caused by neurokinin A. Application of C-PTIO significantly reduced SNP-induced cGMP accumulation in the muscle, as well as the SNP-induced inhibition of muscular contraction caused by carbachol. Neither carbachol nor neurokinin A influenced SNP-induced cGMP accumulation in the muscle. Induction of 8-bromo-cGMP significantly diminished the muscular contraction caused by carbachol but not that caused by neurokinin A. In vivo pretreatment of the eye with LPS increased, in a time-dependent manner, the cGMP accumulation in the iris sphincter muscle, which was significantly inhibited by pretreatment of NG-nitro-L-arginine methyl ester (an inhibitor of NO synthesis) in vivo.

CONCLUSIONS

These results demonstrate that in rabbits the increase in cGMP accumulation induced by NO in the iris sphincter muscle is involved in the cholinergic contraction but not in the tachykinergic contraction, suggesting that different sensitivities to cGMP are essential for the different responsiveness to NO. Furthermore, the results of this study showed that the NO-cGMP pathway is operative in vivo and regulates iris sphincter muscle tone, at least when the eyes are infected with bacteria.

Enhancement by monochloramine of the development of gastric cancers in rats: a possible mechanism of Helicobacter pylori-associated gastric carcinogenesis

The effects of cytotoxic monochloramine on the development of gastric cancers induced by N-methyl-N'-nitro-N-nitrosoguanidine were investigated in Wistar rats. After oral administration of drinking water containing the carcinogen and regular chow pellets for 25 weeks, rats received regular chow pellets or chow pellets containing 20% ammonium acetate, and normal tap water or water containing 30 mM sodium hypochlorite, with or without s.c. injection of taurine, until the end of the experiment in week 52. Treatment with both ammonium acetate and sodium hypochlorite significantly increased the incidence of gastric cancers in week 52, while the concomitant use of taurine with ammonium acetate and sodium hypochlorite significantly attenuated the enhanced gastric carcinogenesis. Spectrophotometric examinations revealed that taurine scavenged monochloramine. These findings suggest that Helicobacter pylori-associated gastric carcinogenesis may be mediated by monochloramine.

Brassinosteroids induce entry into the final stage of tracheary element differentiation in cultured Zinnia cells

To elucidate the involvement of brassinosteroids in the progression of tracheary element differentiation in cultured Zinnia cells, we analyzed the effects of uniconazole, an inhibitor of brassinosteroid synthesis, and brassinolide, a biologically active brassinosteroid, on the accumulation of mRNAs for various genes that were expressed in different stages of differentiation. Uniconazole specifically suppressed the accumulation of transcripts for genes that were induced in the final stage of differentiation in association with secondary wall formation and cell death. This suppression was recovered with the addition of brassinolide. These results strongly suggest that endogenous brassinosteroids induce entry into the final stage of differentiation.

Paradoxic uptake of Gd-EOB-DTPA by hepatocellular carcinoma in mice: quantitative image analysis

To determine whether paradoxic uptake of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) occurs only with highly differentiated hepatocellular carcinomas, quantitative image analysis was performed in 37 mice with 133 hepatocellular carcinomas. The results of lesion/ liver signal intensity measurement and relative enhancement calculation indicate that paradoxic positive enhancement occurs independently of cellular differentiation.

Peritoneal cytology and its prognostic value in endometrial carcinoma

BACKGROUND

There has been a controversy about the prognostic significance of positive peritoneal cytology in endometrial carcinoma.

MATERIALS AND METHODS

Peritoneal cytology was obtained at the time of surgery, including systematic retroperitoneal lymph node dissection, in 114 patients.

RESULTS

The incidence of positive peritoneal cytology was 35.1%. The 5-year survival rates of the stage IIIA and IIIC (FIGO, 1988) cases were 82.8% and 58.3%, respectively. In pathological stage I (the disease was histologically confined to the uterine corpus), there was no significant difference in 5-year survival rates between patients with and without positive peritoneal cytology. Though the patients in stage IIIA who had only positive peritoneal cytology were given no postoperative therapy unless they had extrauterine disease, no patients developed recurrence. In stages IIIC and IV, the prognosis was significantly poorer for patients with positive peritoneal cytology than for those with negative cytology.

CONCLUSION

Positive peritoneal cytology is not an adverse prognostic factor endometrial carcinoma if disease is limited to the uterus.

Hard work does not result in a decrease in meal quality: the case of a Japanese farming village

Historically, when Japanese farmers engaged in hard labor, they were likely to increase their carbohydrate intake without increasing intake of other nutrients. After Japan's economic growth started in the 1960s, however, many kinds of food became available and affordable. We investigated whether farmers today have increased the nutrients in their diet in proper proportion to energy expenditures when they are engaged in farming work by comparing the quantity and quality of meals between farmers and other villagers within a small area of a farming village. The quantity of energy and other nutrients increased with farming work, but the amounts of each nutrient per unit of energy did not decrease with the increase in energy intake. The intake of each nutrient relative to the recommended dietary allowance for energy and each nutrient did not decrease with farming work either. It was concluded that the quality of meals of farmers does not decrease with the increasing energy intake for farming work when many kinds of food are available and affordable.

[The inhibitory effects of Arg-Gly-Asp-Ser on attachment of fibroblasts]

Trabeculectomy often fails because of scarring of the filtering bleb, which is caused by the proliferation of fibroblasts. In this study, we investigated the inhibitory effect of Arg-Gly-Asp-Ser (RGDS) oligopeptide, a cell binding domain of fibronection molecules, on the attachment of fibroblasts in vitro and on scarring of filtering bleb after trabeculectomy on rabbits' eyes. The following results were obtained. 1. RGDS inhibited the attachment of rabbit conjunctival fibroblasts significantly (p < 0.01) when it was added to the culture medium at final concentrations of 2 and 5 mg/ml. 2. The administration of 0.2 ml of RGDS solution (5 mg/ml) into the filtering bleb 3 days after surgery caused significant reductions of intra ocular pressure compared with the control maintained the bleb more than 13 days whereas the blebs of the control eyes disappeared within 6 days (p < 0.01). 3. No complications were caused on the eyeballs of the rabbits by the administration of RGDS.