Nucleotide sequence analysis of the gtfT gene from Streptococcus sobrinus OMZ176

The gtfT gene and its upstream region isolated from the Streptococcus sobrinus OMZ176 chromosomal DNA were sequenced. The gtfT gene was preceded by a potential Shine-Dalgarno sequence. The gtfT gene product, glucosyltransferase (GTF), displays a typical gram-positive bacterial signal peptide sequence and both an active site peptide sequence and carboxy-terminal repeats typical of GTFs. The signal sequence is similar to those of other known GTF proteins. The putative active-site peptide sequence of this enzyme was DGIRVDAVD, which was different by one amino acid from the active-site peptide sequence derived from two different types of the S. sobrinus GTFs reported previously (G. Mooser, S. A. Hefta, R. J. Paxton, J. E. Shively, and T. D. Lee, J. Biol. Chem. 266:8916-8922, 1991). The gtfT gene product has three repeated sequences of 51 to 52 amino acids and a partial repeat of 18 amino acids. Another open reading frame (ORF) was detected in the region immediately upstream of the gtfT gene. The upstream ORF showed substantial DNA homology with the gtfS gene isolated from Streptococcus downei MFe28. The inferred amino acid sequence of the upstream ORF has four repeating units and has extensive homology with the repeated peptides coded by the S. downei gtfS gene. These results suggested that the gtfT gene was a typical gtf gene isolated from the mutans streptococci and that the two gtf genes were located in tandem on the chromosomal DNA of S. sobrinus OMZ176.

Importance of Glu-125 in the catalytic activity of human renal dipeptidase

The carboxyl reagent N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) and dansyl-ethylenediamine have shown to inhibit human renal dipeptidase (hrDP) irreversibly in a time-dependent manner. Cilastatin, a competitive inhibitor of the enzyme, partially protected the enzyme from inactivation. To identify the site(s) modified by EEDQ and dansylethylenediamine, the amino-acid sequence of tryptic fragments of modified enzyme were analyzed extensively. A comparison of the determined amino-acid sequences with the predicted primary structure of hrDP revealed that Glu-125 within the Glu115-Arg138 fragment was modified. In consequence, the role of Glu-125 in catalytic activity was investigated by site-directed mutagenesis. Glu-125 was replaced by a glutamine, aspartic acid or cysteine residue. cDNAs for wild-type or mutated enzymes were expressed in CHO cells, and the resulting proteins were purified to apparent homogeneity. The mutated enzyme, Gln-125-hrDP exhibited specific activity of 28.5 U/mg, corresponding to 11.4% of the wild-type. In contrast, Asp-125-hrDP and Cys-125hrDP were found to be inactive (< or = 0.1% of wild-type enzyme). These results suggest that the polarity and/or length of the side chain of Glu-125 residue are important for the enzyme activity.

Effect of total parenteral nutrition on liver mitochondrial function in mature rats

To evaluate the effects of TPN on the hepatic function, the changes in hepatic energy charge levels, oxidative and phosphorylative activities of mitochondria and serum transaminase were studied, using male Sprague-Dawley rats 240 to 250 g in weight. The rats were randomized into three groups. The first group (TPN-V group, n = 6) was infused with TPN solution via the right jugular vein. The number of calories of TPN solution infused daily was adjusted to provide each rat with 80 kcal/kg/day on the 1st day, 160 kcal/kg/day on the 2nd day and 240 kcal/kg/day on the 3rd day. After the 4th day, 240 kcal/kg/day was given to both groups. The second group (TPN-G group, n = 5) was infused with the same solution via an intragastric route and was given the same calories as the TPN-V group. The third group (control group, n = 6) was given a chow diet with the same calories as the TPN group. At the 13th day, all groups were sacrificed, and the hepatic energy charge (EC) and phosphorylation rate (PR) of hepatic mitochondria were measured, and liver function tests were done. PR was 101.2 +/- 5.0 nmol/mg protein/min in control group, 120.8 +/- 2.7 in TNP-G group and 136.5 +/- 6.2 in TPN-V group. EC was 0.906 +/- 0.006, 0.889 +/- 0.008, 0.831 +/- 0.010, respectively. The liver function tests of all group were normal. In both TPN groups, despite evidence that liver function tests were normal, enhanced mitochondrial phosphorylative activity was observed during the early stage of TPN.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypoosmotic swelling test with a medium of distilled water

The functional competence of the human sperm membrane is assessed by studying the swelling reaction of sperm when suspended in a medium of distilled water (water test). Eighty-seven patients with idiopathic infertility were investigated by the water test and the results were compared with various semen parameters. High correlations with the percentage of b-g type swollen sperm in the water test were observed for sperm concentration (r = .53, p < .05) and percent motility (r = .62, p < .01). The sperm swelling values obtained by the water test correlated well with those obtained by the hypoosmotic swelling test (HOST). Correlation coefficients in b-g and g swelling pattern were 0.89 and 0.71, respectively. The percentage of g-type swelling obtained by the water test was significantly larger than that obtained by the HOST (p < .05), although the two hypoosmotic procedures gave similar percentages of b-g swelling pattern. The percentage of g swelling pattern obtained by the water test correlated well with percent motility (r = .70, p < .001). These findings suggest that the water test is more useful for assessing the integrity of the sperm membrane than the HOST. The relationship between this test and subsequent fertility, as well as to other sperm function tests, needs further investigation.

[Interferon-alpha therapy in the myeloproliferative variants of hypereosinophilic syndrome]

Two cases of hypereosinophilic syndrome (HES) that seemed to be myeloproliferative disorders were treated with interferon-alpha (IFN-alpha). Case 1 was a 45-year-old man with HES who was unresponsive to prednisolone. Because Flaum's hematologic grading score was 8 points, he was diagnosed as a myeloproliferative variant of HES. Although his condition was well controlled by hydroxyurea (HU), cardio-pulmonary insufficiency with refractory eosinophilia developed after 4 years. Instead of HU, IFN-alpha dramatically decreased eosinophil counts, and the clinical situation has stabilized since. Case 2 was a 30-year-old man with HES whose grading score was 9 points. IFN-alpha therapy was started when an accelerated phase of neutrophil dominant with chromosomal abnormality (8 trisomy) occurred. However, he died because of no response to IFN-alpha and other chemotherapy. In both cases, studies of eosinophil colony formation revealed no excess of eosinophil colony-stimulating factor from their lymphocytes. Flaum's hematologic grading score was useful for the diagnosis of myeloproliferative variants of HES. IFN-alpha successfully induced hematologic remission in one case, and this therapy may be beneficial for these patients as a first line agent.

[Cyclosporin for pure red cell aplasia caused rapid improvement of anemia and increase of CD4/8 ratio]

Ciclosporine (CS) caused rapid improvement of anemia and increase of CD 4/8 ratio in two patients with pure red cell aplasia (PRCA). One case was a 45 year old female who were unresponsive to steroids, plasmapheresis and high dose cyclophosphamide, and another was a 61 years old man with diabetes mellitus (DM) without any treatment for PRCA. In both cases hemoglobin increased soon after the initiation of CS and CD 4/8 ratio also rose from 0.80 to 1.47 and 1.78 to 1.98, respectively. There was no side effects to interrupt the course of the therapy. CS seems to inhibit the production of cytokines such as IL-2 and IFN-gamma, and it damages the activated suppressor/cytotoxic T cells. CS is an effective drug for not only refractory cases but the first step therapy for the untreated patients.

DNA sequence of the glucosyltransferase gene of serotype d Streptococcus sobrinus

A glucosyltransferase (GTF) gene was cloned into Escherichia coli from serotype d Streptococcus sobrinus OMZ176. Transformed E. coli strain MI expressed water-insoluble glucan synthesizing activity. Restriction enzyme map of pGT31 extracted from MI shows that the enzyme gene exists in the 6.4-KB PstI-fragment inserted into pBR322 vector. DNA sequence analysis indicates that a single ORF (530-5,300) is located in the PstI-fragment. The putative amino-acid composition (1,590 residues) resembles those of other GTF-I enzymes obtained from serotype g S. sobrinus and serotype h Streptococcus downei. However, at the same positions of the sequence, 18 and 142 amino-acid residues are different between serotype d and g, and serotype d and h GTF-I enzymes, respectively. The differences between serotype d and h GTF-Is are distributed in N and C-terminal regions.

Complication of parenteral nutrition composed of essential amino acids and histidine in adults with renal failure

This is a case report on six patients with hyperammonemia that developed while they were receiving total parenteral nutrition (TPN) as a component of renal failure therapy. Clinically, the hyperammonemia presented as mental status changes in all six cases. Four of the six patients with renal failure initially received 400 mL Amiyu in 1400 mL 17% glucose (total = 1800 mL TPN-A) administered over each 24-hour period. Two patients had been placed on 400 mL complete amino acid in 1400 mL 17% glucose (total = 1800 mL TPN-C over each 24-hour period) prior to therapy with TPN-A. Approximately 3 weeks after initiation of TPN therapy with TPN-A, episodes of mental status changes of increasing duration and paroxysms were documented in five of the six patients. In one of the patients receiving TPN-C prior to TPN-A therapy, toxicity was clinically evident only 4 days after initiation of TPN-A. Serum ammonia levels were obtained and found to be elevated in the acute (ie, presenting) stage in all patients. With the discontinuance of TPN-A, ammonia levels normalized uniformly. Mental status also improved in all cases except for the patient with rapid clinical presentation who died 2 weeks after first evidence of clinical toxicity. In cases 1, 2, and 6, serum amino acid analysis in the acute phase showed reduced levels of ornithine and citrulline, the substrate and product, respectively, of condensation with carbamyl phosphate at its entry into the urea cycle. Moreover, levels of arginine, precursor to ornithine, were found to be elevated.(ABSTRACT TRUNCATED AT 250 WORDS)

[A case of parenchymal pulmonary endometriosis with recurrent chest pain]

A 36-year-old woman was admitted to Nagasaki Citizens Hospital because of severe pleuritic chest pain associated with small amounts of hemoptysis. This episode occurred with the onset of her menses 2 months after a surgical abortion. Chest X-ray revealed a nodular shadow in the left middle lung field. ECG showed no abnormal findings. Pulmonary perfusion scintigram and arteriogram showed no evidence of pulmonary thromboembolism. Over the next 5 years she suffered 5 further episodes of chest pain without hemoptysis, in which every episode coincided with her menses and disappeared within several days after the end of the menses. Chest X-rays disclosed transient nodular shadows on 4 of 6 of the above mentioned episodes. In the earlier episodes one nodular shadow was noted in the left upper lobe S5 a. Later, it was accompanied by an additional nodular shadow in the S5b. Those shadows disappeared in accordance with the diminution of chest pain. From these findings the diagnosis of pulmonary endometriosis was confirmed. Consequently, the antigonadotropin danazol was administered for 6 months. After this, she had no recurrence of her symptoms. Catamenial hemoptysis is usually the most striking symptom of pulmonary endometriosis, which might be an important clue for its diagnosis. The case presented here was characterized by severe chest pain with paucity of hemoptysis.

Acrosome-reacted sperm in infertile and fertile men using the triple-stain technique

By means of a triple-stain technique, the acrosome reaction in infertile and fertile males was investigated. The highest correlations with the percentage of acrosome-reacted sperm were found for motile sperm concentration (r = .60, p < .01) and percent motility (r = .58, p < .05). Significant correlations were also demonstrated between acrosome reactivity and both sperm concentration (r = .50, p < .05) and velocity (r = .40, p < .05). There was only a weak correlation between the percentage of acrosome-reacted sperm and that of swollen sperm. The ratio of acrosome-reacted sperm demonstrated in oligoasthenozoospermic patients was significantly lower than that observed in normozoospermic or fertile males (both, p < .05). There was no significant difference in the ratio of acrosome-reacted sperm between normozoospermic and fertile males. However, all the cases in the latter group had 15% or more acrosome-reacted sperm, whereas the parameter was widely distributed in the former group and some in this group had a decreased ratio. It would appear that a disturbance of the acrosome reaction is one of the causes of reduced fertility potential in normozoospermic males.

Inflammatory pseudotumor of the stomach: report of a highly infiltrative case with electron microscopic and immunohistochemical studies

A large, poorly demarcated, elevated lesion over the area ranging from the lower end of the esophagus to the lesser curvature of the cardiac region was examined in a 19 year old woman, and demonstrated an irregular and highly infiltrative proliferation of spindle cells over the full thickness of the gastric wall. Although the spindle cells grew mainly in the submucosa, they penetrated the muscularis propria, leaving intact muscle tissue that formed an irregular, island-like pattern, and reached the subserosa. The cells were identified as myofibroblasts by light microscopy, immunohistochemistry and electron microscopy. The present case is considered to be of an inflammatory pseudotumor due to extremely infiltrative growth of myofibroblasts. This lesion differed from inflammatory fibroid polyp (similarly consisting of proliferating myofibroblasts accompanied by inflammatory cells) in terms of age at onset, tumor size, pattern of cell proliferation and main inflammatory cell component. This report also discusses the relationship between this lesion and a very recently advocated new entity, inflammatory fibrosarcoma of the mesentery and retroperitoneum, which is a tumour closely simulating inflammatory pseudotumor.

Interleukin-4 enhances in vitro mineralization in human osteoblast-like cells

The effect of human interleukin-4 (hIL-4) on mineralization in human osteoblast-like cells was investigated. Confluent cells were incubated with hIL-4 for 16 or 30 days in the presence or absence, respectively, of alpha-glycerophosphate (alpha-GP), which accelerates the mineralization process. hIL-4 (0.3 ng/ml) induced mineralization with 1.9-, 26- and 37-fold increases of hydroxyproline, calcium, and osteocalcin content, respectively, in the presence of alpha-GP. Mineralization was not induced with other cytokines, hIL-1, hIL-2, hIL-6, or mIL-4. hIL-4 also induced mineralization in the absence of alpha-GP in a manner different from that of 1 alpha, 25(OH)2 vitaminD3 (1,25(OH)2VD3). These findings suggest that IL-4 may play an important role in bone formation.

[Trial of in vitro fertilization via epididymal duct aspirated sperm]

We made a trial of our method by which sperm are collected directly from epididymal duct, then subjected to in vitro fertilization. The subjects were a total of 22 cases comprising 14 of obstructed azoospermia and 8 of severe oligoasthenozoospermia, on which the surgery was performed 26 times. Using the microscope, an epididymal duct was directly punctured to make a suction of the fluid or was slightly incised to make a suction of the outflow. Sperms thus collected were preincubated for 4 to 6 hours, then subjected to in vitro fertilization. Condition of collected sperms; 32 x 10(4)-15300 x 10(4) sperms were obtained in real number. Sperm motility rate was 0-82%, averaging 25.0%. Sperm forward motility were fairly good in 18 of 26 test cases. Sperm condition was so poor as to make the insemination impossible in 4 test cases (16%). Fertility rate for cases of obstructed azoospermia was 53% (8/15 test cases) and 63% (55/87 eggs) in the test cases and the number of eggs, respectively, compared with 33% (2/6 test cases) and 5.4% (2/37 eggs), respectively for cases of oligo-asthenozoospermia. Pregnancy; Successful pregnancy was obtained in 2 of the cases of obstructed azoospermia, in each of which sperms were collected from the head of the epididymis, then passed into the maternal body by zygote intra fallopian tubal transfer (ZIFT); with the one case resulting in uneventful delivery in November 1991 and the other in a miscarriage. The above results suggested the present method would become an epoch-making approach in the treatment of severe male infertility.

Recurrence of superficial bladder tumours after transurethral resection

From 1979 to January 1990, 48 patients with newly diagnosed superficial bladder tumours were treated by transurethral resection (TUR) at Toyama Medical and Pharmaceutical University Hospital. The relationship between tumour recurrence and the stage, grade, number, or size of the tumours was investigated. The 1-, 2-, 3-, 4- and 5-year non-recurrence rates were 72%, 63%, 47%, 40%, and 40%, respectively. Non-recurrence rate for pTa tumours was significantly higher than that for pT1 tumours (p < 0.05). There was no relationship between tumour grade and recurrence. The rate of recurrence of multiple tumours was higher than that of single ones. There was no difference in non-recurrence rate between tumours smaller than 1 cm and those of 1 cm or larger. Non-recurrence rate in the instillation therapy group was significantly higher than in the non-instillation group (p < 0.05). It was concluded that patients with multiple or high-stage tumours have the risk of a high rate of recurrence and that intravesical chemotherapy is effective in preventing local recurrence in some patients.

On the stereoselective synthesis of (+)-pinoresinol in Forsythia suspensa from its achiral precursor, coniferyl alcohol

The residue from Forsythia suspensa stems, upon removal of soluble enzymes, has provided the first evidence for a stereoselective coupling enzyme in lignan biosynthesis. This preparation catalyses the preferred formation (ca 65%) of (+)-[8,8'-14C]pinoresinol from [8-14C]coniferyl alcohol in the absence of exogenously provided cofactors; addition of H2O2 had little effect on enantiomeric composition. However, when NAD and malate were supplied, the stereoselectivity of the coupling reaction was significantly enhanced and pinoresinol consisting of ca 80% of the (+)-antipode was obtained. Clearly, the insoluble residue contains a specific coupling enzyme which catalyses (+)-pinoresinol formation from coniferyl alcohol. By contrast, when [8-14C]sinapyl alcohol was employed as substrate, only racemic syringaresinols were formed: this non-stereoselective peroxidase-catalysed coupling reaction presumably accounts for the low levels of (-)-pinoresinol encountered in this system when coniferyl alcohol is used as a substrate.

An extraordinary accumulation of (-)-pinoresinol in cell-free extracts of Forsythia intermedia: evidence for enantiospecific reduction of (+)-pinoresinol

Stereoselective and enantiospecific transformation mechanisms in lignan biogenesis are only now yielding to scientific inquiry: it has been shown that soluble cell-free preparations from Forsythia intermedia catalyse the formation of the enantiomerically pure lignan, (-)-secoisolariciresinol, when incubated with coniferyl alcohol in the presence of NAD(P)H and H2O2. Surprisingly, (-)-pinoresinol also accumulates in this soluble cell-free assay mixture in > 96% enantiomeric excess, even though it is not the naturally occurring antipode present in Forsythia sp. But these soluble cell-free preparations do not engender stereoselective coupling; instead, racemic pinoresinols are first formed, catalysed by an H2O2-dependent peroxidase reaction. An enantiospecific NAD(P)H reductase then converts (+)-pinoresinol, and not the (-)-antipode, into (-)-secoisolariciresinol. Stereoselective synthesis [correction of syntheis] of (+)-pinoresinol from E-coniferyl alcohol is, however, catalysed by an insoluble enzyme preparation in F. suspensa, obtained following removal of readily soluble and ionically bound enzymes; no exogenously supplied cofactors were required other than oxygen, although the reaction was stimulated by NAD-malate addition. Thus, the overall biochemical pathway to enantiomerically pure (-)-secoisolariciresinol has been delineated.

A new bioabsorbable material for rat vascular cuff anatomosis: establishment for the long-term orthotopic liver transplantation model

Rat vascular anastomosis was performed using a newly synthesized bioabsorbable material (LA-GA copolymer) cuffs and the ordinary polyethylene cuffs. The LA-GA copolymer cuff which anastomosed the portal vein and the inferior vena cava were patent and developed no collateral veins even after 6 months, keeping the transplanted liver normal. By contrast, the polyethylene cuff anastomosed portal vein was completely occluded and the collateral veins were highly developed, with the transplanted liver showing the fatty degeneration of hepatocytes and numerous regenerative nodules. It is concluded that the LA-GA copolymer cuff is a suitable material for the short and long term study of rat orthotopic liver transplantation.

Hepatoblastoma in a 2-year-old girl with trisomy 18

A very rare case of mosaic type trisomy 18 associated with hepatoblastoma is described. The patient underwent an extended right hepatic lobectomy at 2 years of age, and the resected tumor was diagnosed as a fetal type dominant hepatoblastoma. The results of chromosome analysis demonstrated that in the peripheral blood and skin, the trisomy 18 cells were 80% and 67%, respectively. On the other hand, although virtually 100% of the cells in the normal liver tissue were 46, XX, about one third of the cells were trisomy 18 in the tumor tissue. At 2 years and 9 months after the operation, the patient was generally healthy and had no evidence of recurrence.

Effect of birth season on case fatality rate of pulmonary tuberculosis: coincidence or causality?

The effects of birth season on the case fatality rate (CFR) of pulmonary tuberculosis were examined in case records of 9206 patients discharged during 1937-1965 from a national hospital for tuberculosis in Tokyo. The CFR was over 60% until 1945, then it decreased down to less than 9% after 1950. Male cases had little variation in their CFR by their birth season, while female cases had a significant variation and showed a significantly higher CFR than the male cases when they were born in January-June. The results suggest that the birth season had a significant influence on the prognosis of pulmonary tuberculosis.

[A case of inflammatory bronchial polyp associated with pulmonary and bronchial tuberculosis]

A 67-year-old man was admitted to our hospital because of cough and sputum. Chest X-ray revealed cavity and consolidation in the right upper lobe. Microscopical examination of stained specimens of sputum disclosed acid-fast bacilli (Mycobacterium tuberculosis). Cough and sputum resolved and cultures of sputum did not yield M. tuberculosis a month after administration of antituberculosis agents. However, a mass shadow in the right upper lobe was found 3 months later. Bronchofiberscopy revealed a polyp with a stalk at the orifice of right upper bronchus, which was elastic, soft in consistency, smooth surfaced, and movable. The pathological findings of the polyp showed non-specific inflammatory granulation which suggested to be inflammatory bronchial polyp. It was appeared in the healing process of bronchial tuberculosis.

[A study on the mass screening system for prostatic diseases]

Between 1984 and 1990, a mass screening for prostatic diseases was carried out on men over 55 years old in cities, towns and villages in Toyama Prefecture, Japan. The total number of subjects examined in the primary study was 1,232, which was 17.7% of the males over 55 years old in these areas. The primary study consisted of inquiry concerning urination, digital examination of the prostate, transabdominal ultrasonography, and determination of tumor markers. A secondary study was indicated for 100 subjects (8.9%) suspected to have prostatic cancer and 169 (15%) suspected to have benign prostatic hypertrophy, but only 92 (35%) of them were actually examined. Prostatic cancer was histologically diagnosed in 3 subjects (0.3%), and benign prostatic hypertrophy was established in 56 subjects (4.5%), who were referred to urologists. Though a high percentage of the population was covered by the primary study the percentage of subjects who received the secondary study among those in whom it was indicated was low. This probably was a reason for the low detection rate of prostatic cancer. An improved system is considered to be needed to increase the efficiency of mass screening for prostatic diseases.

Stimulation of the protein synthesis by fibronectin is specific for untransformed fibroblastic cells

In the preceding paper, we showed that fibronectin (FN) in solution has the ability to stimulate protein synthesis in NIH-L1 fibroblastic cells. We show here that FN stimulated protein synthesis also in other normal fibroblast cell lines, WI-38 and BALB/3T3, but did so only slightly in their transformed cell lines, L1-4NQOH10, WI-38 VA-13 and KN(7)8; and in rat hepatocytes in primary culture and rat liver epidermoid cells (GR-1) it hardly affected the synthesis. Augmentation of the protein synthesis rate was not attributable to stimulation of collagen synthesis. This stimulatory activity of FN was enhanced remarkably by proteolytic digestion of FN with trypsin.

Epidermal growth factor contents in seminal plasma as a marker of prostatic function

Epidermal growth factor (EGF), first identified in extracts from submaxillary salivary glands of adult male mice, acts as a potent mitogen in a wide variety of cells and tissues in culture. Human EGF, a polypeptide of 53 amino acids isolated from human urine, has been identified in several biological fluids, including prostatic fluid and seminal plasma. Epidermal growth factor content in seminal plasma was measured by RIA. The EGF content in seminal fluid did not change after bilateral vasectomy and the first fraction of sample obtained by split ejaculation contained a significantly larger amount of EGF than the second fraction. Seminal EGF originates from the prostate. There was a close correlation between EGF and zinc contents in seminal fluid. The seminal fluid EGF content was lowered in patients with prostatitis and systemic androgen deficiency. The EGF content in seminal fluid seems to be a reliable indicator of prostatic function.

Fibronectin stimulates protein synthesis in cultured fibroblastic cells

Protein synthesis in mouse embryo fibroblastic (NIH-L1) cells was stimulated by addition of fibronectin (FN) to the culture medium as a soluble factor. This stimulatory activity of FN appeared only when the cells were cultured over their saturated density. A hexapeptide (GRGDSP) containing the RGDS cell attachment site of FN could not prevent the stimulation of protein synthesis. Moreover, activity of the stimulatory FN was not affected by inclusion of cytochalasin B, which is known to release FN from cell surface by disorganizing actin cytoarchitecture. These results suggest that the signaling of change in protein synthesis rate by FN may be distinct from signaling involving cell attachment and spreading.

Paracrine effect of folliculo-stellate cells on the growth factor-like action of activin A in anterior pituitary cultures

Several studies have shown that pituitary folliculo-stellate (FS) cells exhibit local functions within the pituitary gland. On the other hand, we have shown previously that activin A increases the number of FSH-producing gonadotropes in cultured rat anterior pituitary cells. In this study, we investigated whether FS cells exert an influence on the action of activin A. FS cells were prepared by culturing the dispersed rat anterior pituitary cells in media containing 15% fetal calf serum and 6 mM glutamine for 15 days. Most cells had the morphological characteristics of FS cells and S-100 protein immunoreactivity, a specific marker of FS cells. The number of FSH cells, which was higher in activin A-treated than in control cultures, was reduced to the control level by incubation with activin A plus conditioned media from FS cell-enriched cultures (FSCM). This inhibitory effect of FSCM was neutralized by a follistatin antibody, but not by anti-S-100 protein or anti-basic fibroblast growth factor. Furthermore, follistatin suppressed activin A stimulated increases in the number of FSH cells in a similar inhibitory pattern to that of FSCM. Meanwhile, the number of FSH cells was not affected by FSCM or follistatin in the absence of activin A. These results suggest that FS cells are involved in the regulation of the function and/or the morphogenesis of the FSH cell-lineage by affecting the action of activin A, and that this paracrine effect of FS cells is mediated by follistatin.