Meiosis-dependent mRNA splicing of the fission yeast Schizosaccharomyces pombe mes1+ gene

The mes1+ gene of the fission yeast Schizosaccharomyces pombe is essential for the second meiotic division. We have cloned a 1.1-kb HindIII fragment containing mes1+ by complementation from an S. pombe genomic library. Sequencing of the genomic and cDNA fragments indicates the existence of one small intron of 75 nucleotides, although both the 5'(G/GTTAGT) and 3'(CAG/T) intron-exon junctions deviate from the consensus sequences proposed for S. pombe. The putative translation product of the mature mes1+ mRNA is a 11-kDa protein of 101 amino acids which has no significant homology to any previously-reported proteins. Disruption of mes1 has no effect on cell growth but causes an arrest of meiosis before the second meiotic division. Northern-blot analysis revealed that mes1+ was preferentially transcribed under conditions of nitrogen starvation. When a h90 homothallic strain was shifted to a nitrogen-deficient medium, a pre-mRNA accumulated and then was gradually processed to generate a mature mRNA. This splicing did not occur in either a heterothallic haploid strain or in a homothallic mei2 mutant strain which was defective in the initiation of meiosis. Expression of the first exon alone was not able to suppress the mes1 null allele. These results indicate that mes1+ is required for the completion of meiosis, that splicing is required for the function of the mes1+ gene, and that this splicing requires the function of the mei2+ product.

Central nervous system abnormalities in chromosome deletion at 11q23

Two Japanese pediatric patients with terminal deletion of the long arm of chromosome 11 are described. Both had the morphological abnormalities of the 11q deletion syndrome, such as prominent epicanthal folds, broad flat nasal bridge with short, upturned nose, short philtrum with carp-shaped mouth, cardiac anomalies and nonprogressive moderate psychomotor developmental delay. Patient 1 is the first case to be reported with 11q deletion with serial magnetic resonance (MR) examinations of cerebral white matter. The initial MR imaging studies demonstrated multiple areas of T1 and T2 prolongation in the cerebral white matter in both patients at the ages of 2 5/12 and 2 1/12 years, respectively. A second MR imaging, performed 1 year after the first in Patient 1, demonstrated slight improvement of the lesions. Neither patient showed clinical deterioration. These results suggest that the lesions were caused by delayed myelination, rather than by demyelination. It is suggested that an unknown factor which is important for myelination is located on the long arm of chromosome 11: perhaps the neural cell adhesion molecule (NCAM).

[Detection of antinuclear antibodies and their significance as disease markers]

The improvement of the quality control in the detection of fluorescent antinuclear antibodies (FANA) have decreased the differences among institutions. However, the positive lower or upper reference limit and the criteria for the determination vary among laboratories. By examining 725 sera from children and 227 sera from healthy adults, we proposed the titers of 160-320 for children and 80-160 for adults as the positive lower limits. The higher positive incidence in the children's sera might be due to some abnormality in the ANA production or the higher sensitivity of the reagents used. The clinical significances of the anti-U1RNP antibody and anticentromere antibody (ACA) in ANA have been described. The anti-U1RNP antibody, present in only MCTD and related disorders, might play some role in the development of Raynaud's phenomenon and symptoms in a case of neonatal lupus erythematosus. ACA was detected in sera not only of CREST syndrome patients but also of PBC patients. The functions and molecular structures of nuclear antigens have recently been extensively investigated. However, the pathogenetic significance of most of the ANA and the mechanism of their production have not been clarified yet.

MR diffusion imaging in Pelizaeus-Merzbacher disease

A case of classical type Pelizaeus-Merzbacher disease was reported. This patient exhibited marked motor and mental developmental delay, and nystagmus, with a positive familial history. Electrophysiological studies, such as on brainstem auditory evoked potentials, blink reflex and somatosensory evoked potentials, suggested marked disturbance of nerve conduction in CNS. T2-weighted magnetic resonance (MR) images revealed non-progressive diffuse T2 prolongation of cerebral white matter after a 2-year interval, indicating congenital hypomyelination in CNS. A newly developed magnetic resonance diffusion imaging method demonstrated the existence of diffusional anisotropy in the corpus callosum, internal capsule, and white matter of the frontal lobe. Although the diffusional anisotropy was considered to depend on the well-developed multiple layers of myelin around the axons, the imaging data of this patient demonstrated that the diffusional anisotropy did not necessarily depend on those multiple layers. These results may indicate the potential usefulness of MR diffusion imaging, combined with electrophysiological studies and conventional MR imaging, for analyzing the lesions of the cerebral white matter.

Sialidase in rabbit blood. Characterization of sialidase purified from rabbit erythrocyte membrane

Sialidase activities of rabbit blood cells and serum were measured. The leucocyte particulate fraction showed the highest specific activity of sialidase towards mixed gangliosides and sialyllactose, and the cytosolic fraction showed for fetuin. Predominant sialidase activity in the blood was detected in erythrocyte particulate fraction when mixed gangliosides were used as substrate. The sialidase for ganglioside was solubilized from the erythrocyte ghosts by using Triton X-100. The solubilized sialidase was purified 1886-fold by sequential chromatographies on DEAE-cellulose, EAH-Sepharose 4B, Octyl-Sepharose CL-4B, Sephadex G-100, concanavalin-A--Sepharose, N-(p-aminophenyl)oxamic acid-agarose and Heparin-Sepharose CL-6B. The optimum pH of purified sialidase was 4.5 for ganglioside mixture, and this enzyme exhibited M(r) = 48,000 by gel filtration. When the purified sialidase was subjected to SDS/PAGE, a major sialidase-active protein band at M(r) = 54,000 and another fainter inactive protein band with M(r) = 115,000 were observed. The purified enzyme was active towards oligosaccharides, gangliosides, fetuin glycopeptide and 4-methylumbelliferyl alpha-D-N-acetylneuraminic acid except for glycoproteins tested. Fe2+, Fe3+ and dithiothreitol significantly inhibited the enzyme activity, while Triton X-100 activated the enzyme. Inside-out vesicles and unsealed ghosts of rabbit erythrocyte showed the sialidase activity for mixed gangliosides but not for resealed ghosts or intact erythrocytes. These results indicate that the active site of this sialidase is oriented mainly on the inside of the erythrocyte membrane and not on the outside. Treatment of rabbit erythrocyte unsealed ghosts with phosphatidylinositol-specific phospholipase C liberated no sialidase activity toward mixed gangliosides from the ghosts.

pH-sensitive dissociation and association of beta-N-acetylhexosaminidase from boar sperm acrosome

beta-N-Acetylhexosaminidase (beta-Hex, EC, 3.2.1.52) was released from cauda epididymal boar sperm by treatment with ionophore A23187, indicating that this enzyme is localized in the acrosome. beta-Hex was extracted on a large scale, with 2% acetic acid containing 0.2% Brij 35, from washed ejaculated sperm. By gel filtration chromatography, beta-Hex was separated into a high-molecular-weight fraction (beta-Hex I) and a low-molecular-weight fraction (beta-Hex I). beta-Hex I, which is predominant under acidic conditions (pH 6.5), dissociated into beta-Hex II under alkaline conditions (pH 7.4). beta-Hex II, converted from beta-Hex I, associated again to form beta-Hex I under acidic conditions. By sequential chromatography on ion-exchange, lectin, gel filtration, and ion-exchange HPLC columns, beta-Hex I and II were purified 1200-fold and 4000-fold, respectively, with a combined recovery of 23% as measured with synthetic substrate. An inhibitor of beta-Hex, O-(2-acetamido-2-deoxy-D-glucopyranosylidene) amino N-phenyl-carbamate (PUGNAC), reduced the in vitro fertilization rate in porcine cumulus-enclosed eggs, but barely changed the rate when cumulus-free eggs were used. beta-Hex I was shown to possess cumulus dispersion activity, suggesting that beta-Hex plays a role in the passing by sperm through cumulus cells before they bind to the zona pellucida.

Effects of caffeine and casein phosphopeptides on fertilization in vitro of pig oocytes matured in culture

Two experiments were conducted to assess the effects of caffeine and casein phosphopeptides (CPPs). One experiment tested the ability of frozen-thawed epididymal spermatozoa from boar (A, B, C), of proven low in vitro fertilization rates, to penetrate pig follicular oocytes. The other experiment tested the ability of ejaculated spermatozoa to uptake Ca2+. In Experiment 1, oocytes matured in vitro were inseminated with spermatozoa (Boar A) in medium that contained 0, 2, 5, 10, 15, and 20 mM caffeine and CPPs (1 mg/ml), or in medium that contained the same caffeine concentrations without CPPs. When CPPs were added to the caffeine-containing medium, significantly higher penetration rates were obtained than when the oocytes were inseminated in the CPPs-free medium. When the oocytes were inseminated with the spermatozoa (Boar A, B, C) in medium that contained 5 mM caffeine and dephosphorylated CPPs (dCPP:1 mg/ml), the penetration rate was significantly lower than when the oocytes were inseminated with the spermatozoa in medium containing 5 mM caffeine and CPPs (1 mg/ml). In Experiment 2, the concentration of Ca2+ in ejaculated spermatozoa of proven low in vitro fertilization rates during incubation in the fertilization medium was determined with fluorescence, Fura2/AM. When the medium contained CPPs, the intracellular concentration of Ca2+ in spermatozoa increased with a peak of 113 nM after 90 min of incubation. The concentration of Ca2+ was gradually decreased in the medium without CPPs. However, addition of CPPs in the medium had no effect on the motility of spermatozoa in Experiments 1 and 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term observations on morphological changes of choledochal epithelium after choledochoenterostomy in rats

Morphological changes of the common bile duct were observed macroscopically and microscopically 20 months after choledochojejunostomy and choledochocolonostomy in rats. The common bile ducts were remarkably dilated in all rats of both experimental models. Choledochal stones consisting of fatty acid calcium and calcium bilirubinate were seen in two of six rats with choledochojejunostomy and two of five rats with choledochocolonostomy. The main pathological change observed in both the groups was remarkable hyperplasia of the choledochal epithelium. Only one rat with choledochojejunostomy revealed normal epithelium with choledochal stone formation. Intestinal metaplasia was seen in two rats with choledochojejunostomy and all with choledochocolonostomy. Squamous pseudostratification of the epithelium indicating atypism was observed in two rats with choledochojejunostomy. Sialomucin producing cells and sulfomucin producing cells were seen in the hyperplastic portion of the epithelium. No malignant alteration of the epithelium was detected. These findings indicate that long-lasting exposure to digestive enzymes and bacteria causes epithelial hyperplasia and further exposure to digestive enzymes plays a major role in appearance of the epithelial atypism. Carcinogenesis of the choledochal epithelium under such an environment will need much more time to be established.

Autoinduction of activin genes in early Xenopus embryos

Activin exhibits a potent mesoderm inducing activity towards the ectodermal tissue (animal cap) of Xenopus laevis blastulae. Thus in order to investigate the role of activin in morphogenesis of early Xenopus embryos, activation of genes for activin beta A and beta B was examined by the reverse transcription polymerase chain reaction. In vivo, activin beta B mRNA appears to be present in embryonic stage 1 whereas beta A mRNA is undetectable prior to gastrulation. beta B and beta A mRNAs were noted to accumulate after stages 9 and 15 respectively. Activin gene expression in Xenopus animal caps was examined after treatment with various concentrations of activin A. Under these treatment conditions, both activin beta A and beta B mRNAs accumulated in a dose-dependent fashion after 24 h. The same effect was noted for treatment with similar concentrations of activin B. Accumulation of mRNAs was inhibited by the addition of cycloheximide to the culture medium, consistent with the proposition that activin gene expression requires certain protein factors. In total, therefore, these data suggest that an autoinduction mechanism is involved in the regulation of activin mRNA levels in normal Xenopus embryos and that this mechanism may play a pivotal role during early embryonic development.

A new attempt to solve the scale-up problem for granulation using response surface methodology

Scale-up from lab to production is always problematic for the development of pharmaceuticals. In granulation, an optimal formulation of binder solution determined in a lab scale is often different than that in a production scale. A new mathematical procedure to solve this scale-up problem is assessed. Granules were prepared in the two manufacturing scales (2- and 5-kg scale) by using a high-speed mixer granulator. In the manufacturing process, the binder solution plays an essential role in the formation of granules with desired physical properties, in close conformity with the manufacturing scale. A computerized optimizing technique based on a response surface methodology was developed to study the scale-up problem in the manufacturing of granules. For this purpose, a new mathematical function was introduced for the first time, which is namely an integrated optimization function. A universal optimal formulation unaffected by manufacturing scale could be obtained by minimizing the integrated optimization function. Predicted values such as yield, mean granule size, and uniformity of granule size agreed well with experimental ones on both scales. Furthermore, the optimized characteristics measured at the production scale coincided well with those obtained at laboratory scale, suggesting that this approach could be very useful in minimizing scale-up problems.

In vitro growth and maturation of pig oocytes

Preantral follicles containing oocytes of 70-89.5 microns in diameter were isolated from pig ovaries and cultured in collagen gel for up to 16 days, in the presence of serum, FSH and oestradiol. Formation of follicular antra occurred as the culture proceeded. The oocytes had been enclosed by granulosa cells and contacts between the oocytes and processes of the enclosing cumulus cells were maintained over the culture period. After 16 days of culture, 30-40% of the oocytes were of normal appearance, and the diameters of about half of these oocytes were larger than 100 microns. When the oocytes grown in vitro were liberated from the follicles and cultured for a further 48 h in modified Krebs-Ringer bicarbonate solution, 6, 30 and 60% of the oocytes larger than 90, 100 and 110 microns underwent germinal vesicle breakdown, respectively. Progression to metaphase II was observed in 40% of oocytes that were over 110 microns in diameter, whereas no oocyte less than 90 microns in diameter resumed meiosis. The relationship between the size and meiotic competence of oocytes was similar for oocytes grown in vitro or in vivo. Oocytes grown and matured in vitro were penetrated by spermatozoa and formed a female pronucleus, but decondensation of the sperm head was incomplete. The results demonstrate for the first time that pig oocytes from preantral follicles can grow up to their final size, acquire meiotic competence, and be penetrated by spermatozoa in vitro.

Scoliosis associated with central core disease

A 12-year-old Japanese girl who had progressive severe scoliosis but with minimal muscle weakness in the extremities was found to have central core disease. In her muscle biopsies obtained from the biceps brachii and paraspinous muscles, there was type 1 fiber atrophy and predominance, as is commonly seen in congenital myopathies, but the core structure was identified only in the former. To determine whether scoliosis is a prominent feature of this disease, we reviewed 10 patients with central core disease in our laboratory and found 6 ambulant patients who had mild-to-moderate scoliosis. Since kyphoscoliosis becomes prominent as muscle weakness progresses to loss of ambulation in most muscle diseases, this disproportionate spinal involvement in central core disease appears to be a striking feature. All patients with 'idiopathic' scoliosis deserve a careful neurological evaluation, even if they have minimal muscle symptoms in the extremities.

[Effects of rHuEPO on cellular proliferation and endothelin-1 production in cultured endothelial cells]

To elucidate the effects of recombinant human erythropoietin (rHuEPO) on endothelial cell proliferation, protein synthesis and endothelin-1 (ET) production by endothelial cells were examined in a cultured endothelial cell (EC) system. EC, incubated with various concentrations of rHuEPO (0, 1000, 5000, 10,000mU/ml) for up to 3 days exhibited dose-dependent cellular proliferation that could be inhibited by anti-rHuEPO rabbit antiserum. DNA and protein synthesis, measured by the uptake of 3H-thymidine and 3H-leucine, respectively, showed dose-dependent increases after incubation of confluent EC in the resting phase of the cell cycle with various concentrations of rHuEPO (0, 1000, 2500, 5000, 10,000mU/ml) for 18 h. After an additional 6-h culture with rHuEPO at 5000mU/ml or more, the supernatant concentrations of immunoreactive ET showed significantly greater values than those without rHuEPO. Furthermore, rHuEPO increased the DNA synthesis by EC, which had been cultured in E-BM medium containing 0.5% or 2% FBS for 3 h, and which were recultured in E-BM medium containing 5% FBS or containing 2% FBS with 10 ng/ml EGF for 15 h. These results suggest that rHuEPO directly stimulates EC proliferation as a competence factor, and also accelerates endothelin-1 production in association with stimulation of DNA and protein synthesis by EC.

Another family with tricho-rhino-phalangeal syndrome type III (Sugio-Kajii syndrome)

Tricho-rhino-phalangeal syndrome Type III (TRPS III) is a newly defined genetic entity. Only 9 patients in a family and one sporadic patient have been reported. We add another family in which 4 individuals in 3 generations are affected with this autosomal dominant trait. Although they manifested short stature, sparse hair, "pear-shaped" nose, and cone-shaped epiphyses, sharing these findings with TRPS Type I, the presence of a severe form of generalized shortness of all phalanges and metacarpals, and the absences of mental deficiency and exostoses in this family distinguish the disorder from the TRPS Types I and II. Their manifestations are quite similar to those of the patients reported as TRPS III (Sugio-Kajii syndrome).

Change of lipoprotein (a) and coagulative or fibrinolytic parameters in diabetic patients with nephropathy

Lipoprotein (a) (Lp(a)) is a plasma lipoprotein of high atherogenicity and competes with plasminogen at the site of plasminogen receptors. It is known that diabetic patients show a hypercoagulable state which might contribute to diabetic vascular complications. In the present study, mean levels of plasma Lp(a) and parameters of coagulation and fibrinolysis such as thrombin-antithrombin III complex (TAT) and alpha 2 plasmin inhibitor-plasmin complex (alpha 2PIC) were elevated in diabetic patients with nephropathy compared to healthy controls. A significant positive correlation was observed between the plasma levels of Lp(a) and alpha 2PIC (p < 0.05). Plasma levels of alpha 2PIC showed a significant positive correlation with those of TAT in the diabetic group, while there was no significant correlation observed in the non-diabetic group. The present results suggest that factors of Lp(a) and coagulation-fibrinolytic systems interacted, contributing to vascular complications in diabetic patients with nephropathy.

[Intermittent methylprednisolone pulse therapy for myasthenia gravis in childhood]

We studied the effects of the intermittent methylprednisolone pulse (IMP) therapy without the maintenance steroid therapy for 6 children with myasthenia gravis; 3 cases with generalized type and 3 with ocular type. None of them was controlled satisfactorily by oral steroid therapy or anti-choline esterase agents. Two cases with generalized type and the other two with ocular type achieved remission by the initial pulse therapy, and were kept under good control by subsequent IMP therapy performed periodically or at the time of relapse. The other two cases could not be introduced to complete remission by the initial pulse therapy, but improved gradually by subsequent periodical IMP therapy. The IMP therapy without maintenance of oral steroid therapy is more useful as compared with oral administration of steroids, in controlling myasthenia gravis and also in preventing side effects due to steroid therapy.

Japanese type of spondylo-metaphyseal dysplasia

Five members of a Japanese family with a new form of spondylo-metaphyseal dysplasia (SMD) are reported. Another member was also probably affected. The disease was characterised by severe coxa vara, moderately severe metaphyseal changes of the long bones of the lower limbs, mild changes in the long bones of the upper limbs and grossly normal short tubular bones. Platyspondyly, present in the boys, was less marked in their father, whereas two affected aunts had normally shaped vertebral bodies.

Native zona pellucida structure is required for completion of sperm acrosome reaction in porcine fertilization

In fertilization in vitro, the penetration rate of zona-intact porcine oocytes by cryopreserved epididymal spermatozoa was about 100% while that of zona-free oocytes was only 30%. Spermatozoa treated with calcium ionophore A23187 penetrated both zona-intact and zona-free oocytes at the rate of more than 90%. Treatment of spermatozoa with solubilized procine zonae pellucidae hardly induced acrosome reaction and did not increase the penetration rate. These results suggest that the structure of the zona is necessary for completion of acrosome reaction.

Importance of bicarbonate/CO2 for fertilization of pig oocytes in vitro, and synergism with caffeine

Fertilization of pig oocytes was performed in vitro in modified Tyrode's media in which either HEPES or bicarbonate/CO2, or both, were included as buffer systems; caffeine (2 mM) was also included in some of the media because it is a reported stimulant of fertilization. The composition of the bicarbonate-containing media was designed so as to maintain the same pH and osmolality as bicarbonate-free media. The inclusion of bicarbonate during gamete co-incubation in caffeine-containing medium led to high levels of fertilization (66% of 238 mature oocytes were fertilized). However, essentially no fertilization occurred if bicarbonate was replaced with HEPES (0.7% of 146 oocytes were fertilized; significantly different, P < 0.001). Inclusion of HEPES in bicarbonate-containing medium during gamete co-incubation did not affect fertilization, showing that HEPES did not exert an inhibitory effect. Omission of bicarbonate during sperm preincubation also did not affect fertilization. If caffeine was included in bicarbonate-containing medium, 73% of 311 oocytes were fertilized whereas if caffeine was omitted only 14% of 326 oocytes were fertilized (significantly different, P < 0.001). In the absence of bicarbonate, when fertilization was very low, caffeine had no stimulatory effect. The results indicate that bicarbonate is essential for pig fertilization in vitro, but that caffeine exerts a synergistic stimulatory effect.