Isolation of a novel chick homolog of Serrate and its coexpression with C-Notch-1 in chick development

Intercellular signaling mediated by the transmembrane proteins, Notch as receptor and its ligands, Delta and Serrate, plays essential roles in the developmental fate decision of many cell types in Drosophila. The Notch genes are highly conserved both in invertebrates and in vertebrates, suggesting that Notch pathway regulates cell fate decisions during vertebrates development. Notch, Delta and Serrate homologs in chicken have been cloned (Henrique et al., Nature 375: 787-790, 1995; Myat et al., Dev. Biol. 174: 233-247, 1996). We isolated a novel chick homolog of Drosophila Serrate, named C-Serrate-2, and examined its expression patterns during the early chick development using whole-mount in situ hybridization. C-Serrate-2 transcripts were detected in several tissues including the forebrain, the myotome and the apical ectodermal ridge (AER) of the limb bud of a 4-day-old chick embryo. In most of the regions where C-Serrate-2 was expressed, C-Notch-1 was also expressed. Our observations suggest that Serrate-2-Notch-1 signaling plays a role in a variety of morphogeneses during the chick development.

Atopic dermatitis successfully treated by eradication of Helicobacter pylori

A relationship between allergic diseases and Helicobacter pylori infection has recently been noted. We report a case of atopic dermatitis and H. pylori infection in a 14-year-old girl. She had had widespread diffuse skin erythema with erosions and pigmentation since the age of 3 years. Endoscopically, there was chronic antral gastritis with H. pylori infection and histological eosinophilic infiltration. A high titer of H. pylori-specific IgG was present in serum. She was treated with a proton pump inhibitor (lansoprazole 60 mg), an antibiotic (clarithromycin 800 mg), and plaunotol (a mucosal protective agent, 480 mg) for 2 weeks to eliminate the infection. After 10 days of treatment, erythema and itching were more widespread and vesicle formation was seen on the foot. Generalized skin lesions abated a few days later. After eradication of the bacterium by the treatment, eosinophils decreased from 38.8% to 19.0%, and the clinical signs of atopic dermatitis almost disappeared. Serum gastrin level and the pepsinogen I/II ratio were normalized and histological findings of gastric mucosa showed improvement. H. pylori-specific IgE antibody, analyzed by the Western blot method, gradually decreased with the eradication treatment.

Sofalcone for treatment of Helicobacter pylori infection

It is difficult to regard sofalcone as a single drug for the treatment of Helicobacter pylori infection. However, sofalcone exerts multiple effects against H. pylori: it has antibacterial activity, induces morphological changes, inhibits adhesion to gastric mucin and inhibits lipolytic activity. The safety profile of sofalcone even on long-term administration is well established. Therefore, it may be possible to establish a new triple therapy for H. pylori infection using sofalcone combined with antibacterial drugs and proton pump inhibitors.

Helicobacter pylori infection delays the healing of acetic acid-induced gastric ulcer in Japanese monkeys

To clarify the relationship between Helicobacter pylori and the healing of gastric ulcers, we investigated the healing of acetic acid-induced gastric ulcers in the antral mucosa of Japanese monkeys (n = 5) infected with H. pylori and in control monkeys without H. pylori infection (n = 6). Using H. pylori-infected Japanese monkeys as an experimental model, gastric ulcers were induced endoscopically with acetic acid. Healing of ulcers and factors that influenced healing were studied. Continuous colonization with H. pylori was confirmed in the infected group throughout the observation period; no H. pylori were isolated from the gastric mucosa of the control group. White scarring was not observed in any infected monkeys 4 weeks after ulcer formation, but was observed in one (20%) of five monkeys at 6 weeks and in all five monkeys eight weeks after ulcer formation. In the control group, white scarring was observed in one (16.7%) of six monkeys at 4 weeks and in six monkeys at 6 (P < 0.01 vs infected group) and 8 weeks. The ammonia concentration of the gastric secretions and the grade of inflammation were significantly increased in the H. pylori-infected group compared with the control group (P < 0.01 and P < 0.001, respectively). The volume of intracellular PAS-positive substance was decreased (P < 0.025-0.01) at the ulcer margin in the infected group compared with the ulcer margin in the control group. The proliferation of gastric epithelial cells was markedly accelerated at the ulcer margin in the infected group compared with the ulcer margin in control group (P < 0.025-0.01). Our results strongly suggest that H. pylori infection delays the healing of gastric ulcers.

Development of an advanced Kirkpatrick-Baez microscope

We have developed an advanced Kirkpartrick-Baez (AKB) x-ray microscope to diagnose laser-produced plasmas. The AKB microscope is composed of two pairs of hyperbolic and elliptic mirrors to avoid spherical aberration and field obliquity. The spatial response of the microscope has been measured by x-ray backlighting a fine grid with laser-plasma x rays. A spatial resolution of better than 3 microm has been obtained with 2.5-keV x rays over the field of 800 microm at a magnification of 25. This microscope has been applied for laser implosion experiments, resulting in high-resolution images of the compressed cores.

Nickellike soft-x-ray lasing at the wavelengths between 14 and 7.9 nm

We report what we believe is the first observation of clear soft-x-ray lasing in Ni-like Ag, Te, La, Ce, and Pr and also in Nd covering the spectral range 14.3-7.9 nm. A curved slab target was irradiated with quadruple 1.053-microm laser pulses. The pulse-to-pulse separation for the first three pulses was 400 ps, and that between the third and the fourth pulses was 1.6 ns. The pulse duration and irradiance on the target were 100 ps and ~7 x 10(13) W/cm(2), respectively. For all the targets the most intense lasing was observed at the fourth pump pulse.

[Preparation of specific antiserum of secretin and its use in time-resolved fluoroimmunoassay]

We have prepared a specific anti-secretin antiserum and developed a sensitive time-relevant fluoroimmunoassay (TR-FIA) for secretin. An anti-secretin antiserum was produced in rabbit by immunization with synthetic secretin C-terminal 8 residue conjugate to chicken serum albumin as antigen. The TR-FIA was based on the competition between free secretin and biotinylated secretin as a tracer for rabbit anti-secretin antibodies on a goat anti-rabbit IgG antibody coated microtiter plate. After separation of bound and free fractions, a solution of europium (III) ion chelate labeled streptavidin (Eu-SA) was added to the biotinylated secretin bound on the microtiter plate. The microtiter plate was washed and then Eu-SA activity was measured by time-resolved fluorometry. In this TR-FIA, the measurable range of secretin was from 2.5 to 100 pg/assay and the specificity was less than 0.01% against other peptide hormones. For the measurement of secretin in the human plasma, a sample was required for the pretreatment in order to separate from interfering substances. The mean recovery of secretin using commercially reverse phase column was 80.2% (n = 11). The plasma secretin concentrations of normal subjects and those with various diseases could be measured by this proposed TR-FIA.

General pharmacology of the new antimuscarinic compound vamicamide

The general pharmacology of the new antimuscarinic compound vamicamide (FK176, (+/-)-(2R*, 4R*)-4-dimethylamino-2-phenyl-2- (2-pyridyl)valeramide, CAS 132373-81-0) was investigated using mice, rats, guinea pigs and dogs, and was in part compared with that of oxybutynin hydrochloride (oxybutynin, CAS 1508-65-2), a similar type of compound. 1. Vamicamide induced mydriasis after oral administration (p.o.) of 10 mg/kg or more, and suppressed defecation after 32 mg/kg or more in the general activity and behavior test with rats. 2. Vamicamide increased spontaneous locomotor activity in mice at 32 mg/kg or more (p.o.) and suppressed tonic convulsions in the electroconvulsive shock test with mice at 100 mg/kg. The compound at 10-100 mg/kg (p.o) did not show significant effects on hexobarbital-induced anesthesia, pentetrazole-induced convulsions and pain response by Haffner's method in mice, body temperature in rats or spontaneous electroencephalogram (EEG) in rabbits. On the other hand, oxybutynin increased high voltage slow waves of spontaneous EEG in rabbits at 32 mg/kg or more (p.o.) and prolonged hexobarbital-induced anesthesia time in mice at 100 mg/kg. 3. Vamicamide in concentrations of 0.001-1% (1 x 10(-4)-1 x 10(-1) g/ml) did not show local anesthetic effect on the corneal reflex test with guinea pigs. The compound in concentrations of 1 x 10(-5) and 1 x 10(-4) g/ml also had no effects on contractions of the isolated rat diaphragm caused by electrical stimulation of the phrenic nerve. 4. Vamicamide on the highest concentration of 1 x 10(-4) g/ml augmented contractions of isolated rat vas deferens induced by noradrenaline, resting tonus of the isolated guinea pig trachea, and contractile force of spontaneous movement of the isolated rat nonpregnant uterus. The compound at 1 x 10(-4) g/ml had no significant effects on KCl-induced contraction of the isolated rat thoracic aorta. 5. Vamicamide elevated systemic blood pressure and increased heart rate but had no effects on respiratory movement of the chest in conscious dogs at an oral dose of 10 mg/kg or more. The compound in intraduodenal (i.d.) doses of 3.2-32 mg/kg had no effect on femoral blood flow in anesthetized dogs. Vamicamide augmented contractile force and reduced beating rate in isolated guinea pig atria at a concentration of 1 x 10(-5) g/ml or more. Oxybutynin increased heart rate at 3.2 mg/kg or more (p.o.), and elevated blood pressure at 10 mg/kg or more in conscious dogs. 6. Vamicamide slightly inhibited small intestinal transit in rats at 3.2 mg/kg or more (p.o.). On the other hand, oxybutynin inhibited the transit in rats at 0.32 mg/kg or more. 7. Vamicamide had no effects on urine volume, urinary excretion of Na+, K+, Cl- and uric acid in rats at an oral dose of 100 mg/kg or less, or on renal function in anesthetized dogs at an i.d. dose of 32 mg/kg or less. 8. Vamicamide showed no effects on bleeding time in mice at 100 mg/kg p.o., rabbit platelet aggregation induced by adenosine diphosphate or collagen at 1 x 10(-4) g/ml, blood coagulation systems in rats at 100 mg/kg p.o., or hemolysis on rabbit blood at a concentration of 1% or less. Thus, vamicamide in the doses used inhibited gastrointestinal motility, and caused mydriasis as effects possibly due to its anticholinergic action. The compound had no effects on the central nervous system, cardiovascular system, renal functions, or blood system.

[Serum pepsinogen response to therapy for Helicobacter pylori associated gastro-duodenal disease]

We investigated the effect of H. pylori therapy on serum concentrations of pepsinogens on 87 patients of gastro-duodenal disease. In addition, we intended to see whether serum pepsinogen can serve as markers of response to H. pylori eradication. In 48 successfully eradicated cases, there was a significant decrease in gastritis score, and was a significant fall in serum pepsinogen II (PG II) level, and was a significant increase in pepsinogen I/II ratio (PG I/II ratio). In contrast, no change in gastritis score, PG II, and PG I/II ratio were observed in 39 unsuccessfully eradicated patients. No change in serum pepsinogen I (PG I) level was observed in both groups. In provisional successfully eradicated cases in PG II of decrease greater than 30% in after treatment, there was a sensitivity of 83.3% and a specificity of 89.7%. For the PG I/II ratio of increased greater than 30% in after treatment, the sensitivity was 95.8%, and the specificity was 94.9%. These findings suggest that PG II, PG I/II ratio can be useful for clinical evaluation of eradication therapy.

Influence of Helicobacter pylori infection and the effects of its eradication on gastric emptying in non-ulcerative dyspepsia

AIM

The aim of the present study was to clarify the effects of Helicobacter pylori infection and its eradication on gastric emptying.

SUBJECTS AND METHODS

Out of a total of 52 patients with non-ulcerative dyspepsia, 34 H.pylori-positive patients were enrolled. Antimicrobial drugs for the eradication of H. pylori were administered to 19 out of the 34 H. pylori-positive patients. Gastric emptying was evaluated according to the acetaminophen method. Inflammatory changes and intracellular periodic acid-Schiff-positive substances in the antral mucosa were examined in biopsy specimens.

RESULTS

Although gastric emptying was significantly prolonged in the patients with non-ulcerative dyspepsia compared with the control group (P < 0.01), there was no difference in gastric emptying between H. pylori-positive and -negative patients, with all patients showing significantly less gastric emptying than the control group. The H. pylori eradication rate was 58% (11 out of 19) and gastric emptying improved significantly in seven patients whose infection was eradicated and whose dyspeptic symptoms disappeared. The ammonia concentration in gastric juice, inflammatory changes in the gastric mucosa and the index of periodic acid-Schiff-positive substances improved significantly when H. pylori was successfully eradicated compared with patients in whom eradication was unsuccessful. As gut hormones may affect gastroduodenal motility associated with H. pylori infection, we also studied the levels of serum gastrin and cholecystokinin. In the patients whose infection was eradicated, serum gastrin decreased significantly, but the cholecystokinin level did not change significantly, although there was a non-significant trend for cholecystokinin to increase.

CONCLUSIONS

These results suggest that delayed gastric emptying is partly associated with H. pylori infection and that the infection may contribute to the development of non-ulcerative dyspepsia.

From lens regeneration in the newt to in-vitro transdifferentiation of vertebrate pigmented epithelial cells

Through studies to clarify the cellular origin of lens regeneration in the newt, the pigmented epithelial cells of the iris and the retina of many vertebrate species have been shown to possess a dormant potency to transdifferentiate into the lens. The method of in-vitro culture of pigmented epithelial cells has been optimized to enable detailed studies of the transdifferentiation process by molecular techniques. Growth factors and extracellular matrix components are found to be important in the control of the transdifferentiation process. New systems for in-vitro culture are introduced, while prospects for renewed in-vivo studies using newts are given.

Subnanosecond In-Line Soft X-Ray Holography Using Germanium Laser in the 20 nm Wavelength Region

Near- and far-field characteristics of a germanium soft x-ray laser at the wavelengths of 23.2-23.6 nm (J = 2-1 transitions) and 19.6 nm (J = 0-1 transition) are given for quantitative evaluation of the germanium laser for holographic applications. In-line Gabor holography of simple structured objects, such as thin opaque fibers and a standard electron microscope test specimen, is demonstrated. The holograms were recorded on PMMA (polymethyl methacrylate) photoresists and llford Q-plates. The holograms recorded on PMMA were retrieved with an atomic force microscope. The object image was reconstructed by numerical reconstruction with phase retrieval algorithm, resulting in a clear, ghost-free image with sharp edges which infer sub-μm resolution. Future directions for x-ray laser holography are briefly discussed.

Significant improvement in the efficiency and brightness of the J = 0-1 19.6-nm line of the germanium laser by use of double-pulse pumping

We describe significant improvement in the efficiency and brightness of the J = 0-1 19.6-nm line of the neonlike germanium laser. A curved slab target was irradiated by two laser pulses of 100-ps duration separated by 300 ps with a total energy of 200-300 J on target. Compared with that obtained by 1-ns single-pulse pumping with 1.1 kJ of energy, the J = 0-1 line has a 12 times higher peak intensity, with a smaller beam divergence of 2 mrad, corresponding to a factor-of-25 improvement in brightness.

Combination therapy with clarithromycin and sofalcone for eradication of Helicobacter pylori

OBJECTIVE

To clarify the efficacy of combination therapy with clarithromycin and sofalcone for eradication of Helicobacter pylori.

DESIGNS

We studied 42 patients with H. pylori-positive gastroduodenal diseases, who were divided into two groups according to treatment period. Group 1 comprised 27 patients (seven with gastric ulcers, 14 with duodenal ulcers and six with gastritis) treated with a combination of clarithromycin (200 mg, three times a day) + sofalcone (100 mg, three times a day) for 3 weeks. Group 2 comprised 15 patients with chronic active gastritis treated with the same doses of clarithromycin + sofalcone but for only 2 weeks (group 2). The H. pylori status of all patients was assessed by culture, rapid urease test and histological examination at the end of treatment and 4 weeks after the end of treatment. The gastritis score, the index of intracellular periodic acid-Schiff-positive substance in the antral mucosa and the ammonia concentration in gastric secretions were also estimated before and after treatment.

RESULTS

In group 1, with over half the patients excluded from the follow-up, H. pylori was eradicated in nine out of 13 patients (69.2%) compared with six out of the complete group of 15 (40.0%) patients in group 2, without serious side effects. In these patients, significant improvements were seen in the gastritis score (P < 0.025), the index of periodic acid-Schiff-positive substances in the antral mucosa (P < 0.025) and the ammonia concentration in gastric secretions (P < 0.02) after treatment.

CONCLUSION

These results suggest that modification of the treatment regimen is needed, with higher doses of clarithromycin and combination therapy with proton-pump inhibition.

Establishment of an animal model for chronic gastritis with Helicobacter pylori: potential model for long-term observations

OBJECTIVES

To assess the suitability of an established experimental model for chronic gastritis associated with Helicobacter pylori for use in long-term observations.

DESIGN

In a 3-year follow-up study of acute gastritis induced by H. pylori using an established experimental model with Japanese monkeys, we compared H. pylori-infected animals (n = 6) with a non-infected control group (n = 7). Colonization by H. pylori, gastritis scores, volume of intracellular periodic acid-Schiff-positive substances and the height of antral glands were investigated every 3 months for 3 years and compared with those of a control group.

RESULTS

In the infected group, persistent colonization with H. pylori was demonstrated by culture and histological examinations. Gastritis scores were significantly higher than those of the control group, and the histological findings were quite similar to those of chronic active gastritis observed in humans. Simultaneously, significant decreases in the contents of periodic acid-Schiff-positive substances and in the height of antral glands were also demonstrated in infected animals.

CONCLUSION

In Japanese monkeys, persistent colonization with H. pylori caused chronic gastritis quite similar to that observed in humans, thus providing a suitable animal model for evaluating the long-term prognosis of H. pylori infection.

Gene regulation and differentiation in vertebrate ocular tissues

Molecular biological techniques have contributed greatly to the study of vertebrate ocular tissues. The specification of ocular tissues has been shown to be closely related to the expression of transcription factors encoded by genes such as Pax6 and microphthalmia. Lens-specific expression of the delta 1-crystallin gene is controlled by factors, such as delta EF1, binding to its enhancer sequences. Retinal activity of the glucocorticoid hormone receptor is regulated by its binding with another transcription factor. Degeneration of photoreceptors in a retinal disease, retinitis pigmentosa, can be caused by the introduction of a mutated opsin gene into mice. In addition, the process of transdifferentiation in ocular tissues has been described at the level of gene expression.

A comparative analysis of the costs of administration of an OSCE (objective structured clinical examination)

BACKGROUND

The objective structured clinical examination (OSCE) has become an accepted technique for the evaluation of clinical competence in medicine. Although advances have been made in our knowledge of the psychometric aspects of the OSCE, extremely little has been written about feasibility and cost issues. Given the current economic imperative to control costs and the extremely scant literature on the costs of developing and administering an examination in medicine, the authors felt it timely and relevant to explore issues related to the cost of the OSCE.

METHOD

In 1991-92 and in 1992-93, costs and time requirements to implement and administer a structured oral (SO) examination and a six-station OSCE for a surgical clerkship at the University of Toronto Faculty of Medicine were gathered by review of invoices, interviews with those involved, and perusal of diaries kept by staff.

RESULTS

To develop and administer the six-station OSCE, 327.5 hours of staff and faculty time were required for each rotation of surgical clerks (8.2 hours per student). The SO examination required 110 hours of staff and faculty time (2.75 hours per student). Direct expenses for the OSCE amounted to U.S. $6.90 per student per station, compared with no direct expense for the SO examination.

CONCLUSION

The OSCE was more time-consuming and more expensive in human and material costs than the SO examination. However, costs of the OSCE can be substantially reduced from approximately U.S. $35 to U.S. ! per student per station if test developers, standardized patients, support staff, and examiners can donate their time. The authors compare the costs and time requirements of their OSCE with those of other OSCEs reported in the literature, and they provide guidelines to assist educators in deciding whether the costs of an OSCE are justifiable in the educators' individual settings.

The loss of gap junctional cell-to-cell communication is coupled with dedifferentiation of retinal pigmented epithelial cells in the course of transdifferentiation into the lens

Retinal pigmented epithelial cells (PECs) of the chick embryo can be cultured as a monolayer of melanized hexagonal cells. Modifications of the culture condition make the cells lose most of the phenotypes and further transdifferentiate into lentoid bodies within a few weeks. Ultrastructural observations showed that PECs and the lentoids have gap junctions with distinct morphology. Diffusion of a fluorescent dye confirmed the presence of gap junctions in both phenotypes. However, cells in the intermediate stage of transdifferentiation, which show neither the phenotype of the PEC nor that of the lentoid and are called dedifferentiated PECs here, have almost no gap junction structure. We propose the possibility that the dedifferentiation of PECs and the loss of cell-to-cell communication are tightly coupled events. This cell culture system is a suitable material for further studying this relationship by cellular and molecular approaches.

[Eradication therapy of Helicobacter pylori in gastroduodenal ulcer and its long-term course]

We investigated the efficacy of antimicrobial drugs, amoxicillin and clarithromycin that have the in vitro activity against H. pylori, and observed a long term course of ulcer after eradication. The eradication rate of combination therapy with PPI and amoxicillin showed best result (13/18: 72%). In eradicated cases, index of PAS positive substance and gastritis score in antral mucosa that is histological examination was improved, and ammonia concentration in gastric secretions decreased. The recurrent rate of ulcer in long term course after eradication was investigated, the recurrent rate of ulcer was significantly lower in H pylori eradicated cases than in H. pylori continuously positive cases. Results suggest that eradication of H. pylori may be controlled recurrence of H. pylori positive peptic ulcer.

Transdifferentiation

Recent progress in studies of development and differentiation has greatly stimulated analysis of transdifferentiation, and more cell types capable of transdifferentiation have been documented. Growth factors must be essential, key factors in the regulation of the transdifferentiation process, in cooperation with components of the extracellular matrix, which helps to stabilize the differentiated state of tissues. Trials to induce transdifferentiation artificially by transfection of genes have also begun.

[Experimental study in Japanese monkeys with Helicobacter pylori infection]

Japanese monkeys were studied for one month from 6 months (short-term) after inoculation of Helicobacter pylori, and two years (long-term). In the short-term study, macroscopic and histological gastritis were observed for 5 infected monkeys. The gastritis score, the ammonia concentration in the gastric secretion and the level of serum antibody (IgG) were higher for the infected group than for the control. In the long term study, H. pylori was always recovered for 2 years in the infected group, and the gastritis score was higher than the control. The intracellular periodic acid-Schiff (PAS) positive substances in the infected group decreased than that of the control. The tall of pyloric gland in the infected group was significantly decreased on 6 months from 1.5 years. These results suggest that the Japanese monkey can be used as experimental model of H. pylori infection and that H. pylori can induce chronic active gastritis similar to human.

Retinal differentiation from multipotential pineal cells of the embryonic quail

Pineal cells of the embryonic quail are multipotent stem cells which are able to differentiate in vitro into pigmented epithelial cells, lens cells and skeletal muscle fibers. Neuronal expression was added in this study in the repertory of differentiating potency of pineal cells. We used immunohistochemical methods to characterize neuronal properties with antibodies against serotonin, GABA, tyrosine hydroxylase and neuron-specific antigen (HPC-1) in addition to the enzyme histochemistry for acetylcholinesterase activity. Cells in the culture were found to be positively stained with these methods, suggesting that embryonic pineal cells are neuropotent to differentiate various types of neuronal cells. We have studied the culture conditions which favor increment of neuronal cells with extension of neuritic processes, and we have found that neuronal cells are maintained for quite a long period under suppressive conditions of DNA synthesis and under the effect of basic fibroblast growth factor (FGF). Suppression of DNA synthesis was achieved by the addition of aphidicolin, an inhibitor of DNA polymerase alpha, in the medium. Time lapse videograph revealed two different cell types participated in neurogenesis; a minor population of small round cells and a major one of flat epithelial cells. Since embryonic quail pineal cells have been shown to differentiate into two types of photoreceptors, the present results show wider retinal potency of cell differentiation by embryonic pineal cells. The cessation of DNA synthesis as well as growth factor(s) may be positively involved in the mechanisms of determination and differentiation of pineal neurons.

Basic fibroblast growth factor as one of the essential factors regulating lens transdifferentiation of pigmented epithelial cells

In vitro transdifferentiation of retinal pigmented epithelial cells of the chick embryo into lens cells can be markedly enhanced by culture in the presence of testicular hyaluronidase and phenylthiourea. Since the commercial preparations of hyaluronidase that had previously been used were very crude, a search for the actual effective molecule(s) enhancing lens transdifferentiation was conducted. First, we purified the enzyme and tested the effect of the purified hyaluronidase. Highly purified hyaluronidase itself did not enhance lens transdifferentiation. The crude hyaluronidase was then separated according to affinity with heparin, considering the possibility that the fibroblast growth factor (FGF) is contained in the crude hyaluronidase. Transdifferentiation-enhancing activity was detected in the fraction which was bound to heparin and eluted with 2 M NaCl, where no hyaluronate-degrading activity existed. Analysis of the fraction by SDS-PAGE revealed the existence of an 18 kDa protein whose NH2-terminal sequence was identical to that of basic FGF. The basic FGF derived from bovine brain also enhanced lens transdifferentiation of pigmented epithelial cells. These findings suggest that basic FGF must play a major role in enhancing transdifferentiation of pigmented epithelial cells to lens cells.

[Reproductive and developmental toxicity studies of FUT-187. (I)--Fertility study in rats with oral administration of FUT-187]

FUT-187 was given orally at 20, 120 and 720 mg/kg during the pre-pairing period (63 days prior to pairing in males and 14 days prior to pairing in females) and the pairing period to male and female rats and in the early stage of pregnancy (days 0 through 7 of gestation) to female rats, and the effects of the test compound on male and female reproductive performance and fetal development were evaluated. One male of the 720 mg/kg group died due to treatment. Temporary salivation was observed in males and females in the 20 mg/kg or more groups. In males, increases in the weight of the pancreas in the 120 mg/kg or more groups and the adrenals in the 720 mg/kg group, a depression of body weight gain and decreases in food intake and weight of the carcass in the 720 mg/kg group were statistically significant in comparison with controls. In females, an increase in the weight of the pancreas in the 120 mg/kg or more groups, a slight depression of body weight gain during the early stage of pregnancy and a decrease in the food intake, and a decrease in the weight of the carcass in the 720 mg/kg group were statistically significant in comparison with controls. No dose-related changes were found in the estrus, copulation, insemination and fertility indices. In fetuses, decreased numbers of corpora lutea, implantation and live fetuses were observed in the 720 mg/kg group. There were no treatment-related abnormalities in fetal mortality, sex ratio, weights of fetuses and placenta, and external and visceral examinations. Based on these results, it is concluded that the no-effect-dose levels of FUT-187 are less than 20 mg/kg for the parents, 720 mg/kg for reproductive performance and 120 mg/kg for fetal development.

Development of a Schwarzschild-type x-ray microscope

A Schwarzschild-type x-ray microscope has been designed, constructed, and tested. Ni/C multilayers were used as the x-ray mirrors, with a thickness (2d) of 7 nm and 30 layer pairs. The microscope has attained a spatial resolution of 0.5 microm at a magnification of 15. By using bright laser-produced plasmas as an x-ray source [R. Kodama, K. Okada, N. Ikeda, M. Mineo, K. A. Tanaka, T. Mochizuki, and C. Yamanaka, J. Appl. Phys. 59, 3050 (1986)], images could be recorded during the 400-psec laser pulse.

Ultrastructural observations of typical gap junctions in human foetal lens nucleus

The ultrastructure of gap junctions throughout the human foetal lens was observed. By freeze-fracture analysis, we observed numerous gap junctions in both lens cortex and lens nucleus. Comparison between lens cortex and lens nucleus showed that the gap junctions of lens nucleus are characterized by extreme mosaics of closely apposed P- and E-faces in junctional areas, though no significant difference in the area of gap junctions was observed between lens cortex and lens nucleus. In addition, some morphological variations, such as the smooth domains without particles or pits in junctional areas and the reticulated figures of gap junctions, were observed only in the lens nucleus. We also observed by thin-section electron microscopy that cell membranes of human foetal lens nucleus, as observed in the lens cortex, are mainly composed of continuous lipid bilayer and junctional structures. We concluded that characteristic morphology of lens gap junctions, as observed in the cortex of human foetal lens, is mostly preserved in the human foetal lens nucleus, although some depth-dependent alterations were also observed.

Ultrastructural and immunocytochemical analysis of the circumferential microfilament bundle in avian retinal pigmented epithelial cells in vitro

The dedifferentiated phenotype of pigmented epithelial cells in vitro is bipotential and is effected by environmental alterations mediated by the cell surface and associated cytoskeleton. We have begun an investigation into the role that contractile microfilaments play in maintaining cell contact and cell shape in retinal pigmented epithelial cells in vitro. In this paper, we report a structural analysis of the intersection of the circumferential microfilament bundle with the cell membrane of cultured pigmented epithelial cells from chick retina. Techniques of electron microscopy, including freeze-fracturing and deep-etching, reveal that microfilaments of this bundle associate with a junctional complex in the apical cell compartment and with membrane domains which are not components of the junction. Microfilaments link with the cell membrane either at their termini or along the membrane-apposed surface of the circumferential bundle. Furthermore, we report the immunocytochemical localization of filamin (a high molecular weight actin-binding protein, which forms fiber bundles and sheet-like structures when bound with F-actin in solution) in the circumferential/microfilament bundle.

[Fifty two-week chronic oral toxicity study of mofezolac (N-22) in beagle dogs]

The chronic toxicity study of mofezolac (N-22), a new developed analgesic and anti-inflammatory agent, was carried out in beagle dogs by oral administration of the test compound at dose levels of 1, 3, 6 and 12 mg/kg once daily for 52 weeks. The recovery study was also carried out by withdrawal for 5 weeks. 1. No death occurred during the administration and recovery periods in all groups, there were no abnormal findings due to N-22 administration on behavior and appearance, body weight and food consumption. 2. There were no abnormal findings due to N-22 administration on fecal test, urinalyses, hematological and biochemical examinations, hepatic and renal function tests, ophthalmological examination, electrocardiography, blood pressure and organ weight. 3. By histopathological examination, loss of villi in small intestine was found in one female of 6 mg/kg group, erosion in small intestine in one male of 12 mg/kg group, and shortening of villi and ulcer in small intestine in each one female of 12 mg/kg 4. Accordingly, the non-effective dose levels of N-22 were estimated to be 6 mg/kg for male and 3 mg/kg for female in this study.

Acute toxicity tests of mofezolac (N-22) in mice and rats

Mofezolac (N-22) is a newly developed analgesic and anti-inflammatory agent. The acute toxicities of N-22 were investigated in ICR mice and Wistar rats in oral (p.o.), intraperitoneal (i.p.) and subcutaneous (s.c.) routes. LD50 values of N-22 in mice were 1528 mg/kg (p.o.), 275 mg/kg (i.p.) and 612 mg/kg (s.c.) for males, and 1740 mg/kg (p.o.), 321 mg/kg (i.p.) and 545 mg/kg (s.c.) for females. Those in rats were 920 mg/kg (p.o.), 378 mg/kg (i.p.) and 572 mg/kg (s.c.) for males, and 887 mg/kg (p.o.), 342 mg/kg (i.p.) and 510 mg/kg (s.c.) for females. The sex difference was not clearly observed in mice and rats, but the species difference was observed in p.o. routes. As an initial toxic sign, the hypoactivity was observed in mice and rats of all routes, subsequently, paleness of skin, anemic conjunctiva, emaciation, stupor and/or coma were observed in mice and rats of p.o. and i.p. routes. In rats of those routes, tonic and/or asphyxial convulsion and dyspnea were also observed. In pathological examination of mice and rats, gastrointestinal disorders were observed in p.o. and i.p. routes, and changes of subcutaneous tissue at the injection site were observed in s.c. route.

[Reproductive and developmental toxicity study of mofezolac (N-22) (3)--Teratogenicity study in rabbits by oral administration]

Mofezolac (N-22) is a new developed analgesic and anti-inflammatory agent. A teratogenicity study of N-22 was carried out in New Zealand White rabbits to examine the effect on the dams and the teratogenic potentiality. N-22 was administered orally at the dose levels of 12.5, 50 and 200 mg/kg during the organogenesis from day 6 to day 18 of gestation. All pregnant females were sacrificed on day 28 of gestation and their fetuses were examined. There were no growth retardation and teratogenic effects on fetuses from the dams administered N-22, although the administration of 200 mg/kg produced a decrease in food consumption of the dams concomitant with the embryocidal effects as shown by an increase in the early resorption rate. Thus, non-toxic dose level of N-22 on the dams and fetuses was considered to be 50 mg/kg.

[Fifty two-week chronic oral toxicity study of mofezolac (N-22) in rats]

Fifty two-week oral toxicity study of mofezolac (N-22), a new developed analgesic and anti-inflammatory agent, was carried out in Wistar rats with dose levels of 5, 20, 60 and 120 mg/kg/day, and the 5-week withdrawal was followed for recovery study. Hematuria, blanching of the skin and suppression of body weight gain were observed in females given 120 mg/kg, and 9 of these prostrated and died from week 20 to week 52, or were euthanized when moribund. These symptoms were not seen in males at any dose levels. In 120 mg/kg group, increased positive cases of fecal occult blood were observed during the administration period, and the pathological examination revealed gastrointestinal lesions such as erosion, ulcer, hemorrhage and mucosal regeneration in the small intestine. Renal disorder was also involved mainly in females given 120 mg/kg, as shown by increase in urine volume with declined osmotic pressure and specific gravity, serum urea nitrogen, creatinine, inorganic phosphorus, and other related parameters. In addition to enlargement, rough surface and scar formation, dilated tubular lumen and papillary ducts of the kidney were observed as a main lesion. Incidental findings with those disorders, observed mainly in females given 120 mg/kg, included increase in leucocytes with high neutrophils ratio, and enlargement of the spleen, adrenals and mesenteric lymph node. There were some of the similar gastrointestinal and renal changes mainly in females given 60 mg/kg. Anemic findings were noted in both sexes of 120 mg/kg and in females of 60 mg/kg group, and mainly females given 120 mg/kg showed increase in platelets, reticulocytes and fibrinogen, shortening of blood coagulation time, as well as extramedullary or accented hematopoiesis of the liver, spleen and bone marrow. Other serum biochemical changes observed mainly in females given 120 mg/kg were decrease or decreasing trend in total protein, A/G ratio, and transaminase activity. Fine structure of the liver from females given 20 mg/kg or more revealed cisternal dilatation of smooth-surfaced endoplasmic reticulum of hepatocytes, and the increased liver weight was observed in females given 120 mg/kg. Accordingly, non-effective dose level of N-22 in 52-week chronic toxicity study was estimated to be 20 mg/kg for males and 5 mg/kg for females.

Partial amino acid sequence of the major intrinsic protein (MIP) of the chicken lens deduced from the nucleotide sequence of a cDNA clone

A cDNA clone of the major intrinsic protein (MIP) of the chicken lens was isolated. This clone covers the C-terminal half of the coding region and 3'-untranslated region including a polyadenylation signal. Comparison with the bovine MIP cDNA sequence revealed that: (1) the amphilphilic transmembrane helix in bovine MIP is highly hydrophobic in chicken MIP, and is thus unlikely to offer a hydrophilic lining of the transmembrane pore, and (2) the possible calmodulin binding site is conserved especially at amino acid residues which are postulated to be important in its binding with calmodulin. Northern blotting revealed the presence of transcripts of different lengths, two of which correspond closely to the transcripts of bovine MIP.

[Gene expression during lens transdifferentiation from pigmented epithelial cells]

Pigmented epithelial cells of chicken and human dedifferentiate in the medium containing phenylthiourea and testicular hyaluronidase, and then trans-differentiate into lens cells in vitro. To understand the molecular mechanisms of transdifferentiation, gene expression during lens transdifferentiation was analyzed. As the first step, pigment cell and lens specific genes were isolated and expression of these gene was analyzed by Northern blotting . These results clearly shown that lens transdifferentiation proceeds via neutral cell state in which both pigment and lens specific genes are repressed. Oncogene expression was also analyzed. An elevated expression of the c-myc gene was observed during dedifferentiation process. It is expected that elevated expression of c-myc gene might prevent the cells from entering the G0 phase and thus lead to dedifferentiated state.

Ontogenesis of alpha 2-adrenoceptor coupling with GTP-binding proteins in the rat telencephalon

The ontogenesis of alpha 2-adrenoceptors and GTP-binding proteins and their coupling activity were investigated in telencephalon membranes of developing rats. The manganese-induced elevation of [3H]clonidine binding was increased in an age-dependent manner but the guanosine 5'-O-(3-thio)triphosphate-induced decrease in binding did not change. The extent of the binding of [3H]clonidine at 15 nM (saturable concentration) increased in an age-dependent manner and reached the adult level at 4 days after birth. Cholera toxin and pertussis toxin catalyzed ADP-ribosylation of proteins of 46 and 41/39 kilodaltons (kDa) in solubilized cholate extracts of the membranes. The 41/39-kDa proteins ADP-ribosylated by pertussis toxin (Gi alpha + Go alpha) were increased with age and reached the adult level at day 12, whereas the 46-kDa protein (Gs alpha) reached its peak on day 12 and then decreased to the fetal level at the adult stage. The immunoblot experiments of the homogenates with antiserum (specific antibody against alpha- and beta-subunit of GTP-binding proteins) demonstrated that the 39-kDa alpha-subunit of (Go alpha) and the 36-kDa beta-subunit of GTP-binding protein (beta 36) increased with postnatal age. In contrast, 35-kDa beta-subunit (beta 35) did not change. From these results, it is suggested that the coupling activity of alpha 2-adrenoceptor with GTP-binding protein gradually develops in a manner parallel with the increase of alpha 2-adrenoceptor and pertussis toxin sensitive GTP-binding proteins, Gi, and that alpha 39 beta 36 gamma may be related to the differentiation and/or growth of nerve cells in rat telencephalon.

The expression of melanosomal matrix protein in the transdifferentiation of pigmented epithelial cells into lens cells

A monoclonal antibody (MC/1) was constructed against melanosomes purified from the chicken pigmented epithelial cells (PECs) in order to characterize the differentiative phenotypes of PEC in the process of transdifferentiation into lens cells. Immunofluorescent studies revealed that MC/1 antibody specifically stains both retinal PECs in the eye and melanocytes in the skin, of chicken embryos. Immunoelectron microscopy showed that the antigen molecules are located on the peripheral region of the melanosomal matrix. A single protein band with an apparent molecular weight of 115,000 was labelled by MC/1 in Western blotting. The 115 kDa polypeptide identified by MC/1 is considered to be a member of the melanosomal matrix proteins. The maintenance of specificity of pigment cell nature is followed in the system of transdifferentiation of PEC into lens in vitro, utilizing 115 kDa protein as a marker. In the dedifferentiated PECs, this protein was undetectable.

Population inversion in laser-produced plasmas stagnating on a radiative coolant of solid density

Population inversion between the n = 3 and n = 2 levels of the Mg(+11) ion (the wavelength of the transition is 4.5 nm) was observed in a laser-produced plasma that was stagnated and rapidly cooled on a high-Z (Au) plate. The ratio of the population inversion was determined to be 1.4 - 1.8 when the opacity effect was taken into account. From the dependence of the inversion on the coolant's Z number, we found that the major cooling mechanism is radiative heat loss rather than thermal conduction to a cold inner part of the plate.