Activin A and follistatin regulate developmental competence of In vitro-produced bovine embryos

The effects of activin A and/or follistatin on the development of bovine embryos were investigated. Presumptive zygotes matured and fertilized in vitro were cultured in a chemically defined medium (modified synthetic oviduct fluid medium; mSOF). Addition of 1-100 ng/ml of activin A to mSOF significantly increased the percentage of zygotes that developed to morulae and blastocysts (48-54% and 31-41%, respectively) compared with no addition (41% and 25%, respectively). In contrast, addition of 1-100 ng/ml follistatin significantly reduced the percentage of zygotes developing to morulae and blastocysts (29-31% and 17-20%, respectively) compared with no addition (41% and 28%, respectively). In a culture with 10 ng/ml of activin A, supplementation with the same concentration of follistatin neutralized the positive effect of activin A, while supplementation with 100 ng/ml of follistatin reduced the percentage of zygotes that developed. The total cell numbers in morulae and blastocysts were not affected by the addition of activin A and/or follistatin. The development-enhancing effects of activin A and the development-impeding effects of follistatin were observed when embryos were exposed to activin A or follistatin at a concentration of 10 ng/ml prior to the 9- to 16-cell stage. These results suggest that activin A and follistatin may affect bovine embryos until the third cell cycle and may play important roles in regulation of the developmental competence of bovine embryos.

High frequency oscillations in early cortical somatosensory evoked potentials

OBJECTIVE

To evaluate the characteristics of high frequency (HF) components of the early cortical somatosensory evoked potentials (SEPs).

METHODS

We recorded 8-channel SEPs from the frontal and left centro-parietal scalp after right median nerve stimulation with a wide band-pass (0.5-2000 Hz) and digitized at 40 kHz sampling rate in 12 healthy subjects. HF components were analyzed after digital band-pass filtering (300-1000 Hz). The power spectrum was obtained by a maximum entropy method.

RESULTS

HF oscillations (maximum power at 600-800 Hz) consisting of 5 to 8 peaks were discriminated from the preceding P14 far-field in all cases and their phases were reversed between the frontal and contralateral parietal regions. In addition, in subjects with a high amplitude central P22 potential in original wide-band recordings, a single HF oscillation with a maximum at the central region was present. Furthermore, this component showed no phase reversal over the centro-parietal area.

CONCLUSION

We therefore conclude that HF oscillations are superimposed not only on the tangential N20-P20 but on the radial P22 potential, and are generated from both tangential (area 3b) and radial (area 1) current sources.

Postnatal development of Eustachian tube: a computer-aided 3-D reconstruction and measurement study

The postnatal development of the Eustachian tube (ET) and its surrounding structures was investigated by means of computer-aided three-dimensional (3-D) reconstruction methods in 13 normal human temporal bones, obtained from individuals 3 months to 71 years old. The cross-sectional area, width and height of the lumen in most of the cartilaginous portion of the ET were significantly smaller in children than in adults. In particular, there was a marked, age-associated difference in the shape of the lumen in the cartilaginous portion of the ET. In adults, the cross-sectional area of the lumen declined monotonically between a large opening at the pharyngeal orifice and the narrowest portion of the ET (near the border of the cartilaginous and junctional regions). In children, by contrast, the ET lumen was uniformly smaller over the first 80% of its length from the pharyngeal orifice. It is suggested that this immature morphology of the ET lumen may confer increased risk of developing otitis media during childhood.

Fibrosis accelerates the development of enzyme-altered lesions in the rat liver

Injection of pig serum into rats twice a week for 8 weeks induced stellate cell activation resulting in liver fibrosis without parenchymal cell injury. Administration of a choline deficient L-amino acid defined (CDAA) diet for 6 weeks with or without pig serum pretreatment led to the development of preneoplastic lesions that were positive for the placental form of glutathione S-transferase (GSTP). Pig serum pretreatment induced more activated stellate cells in the livers of rats subsequently fed a CDAA diet for 6 weeks compared with rats fed the CDAA diet alone. Activated stellate cells were detected as smooth muscle actin (SMA)-positive cells and by the expression of SMA messenger RNA. These cells caused severe fibrosis as assessed by the hepatic hydroxyproline content. Pre-existing fibrosis induced by the activation of stellate cells with pig serum pretreatment increased hepatic malondialdehyde (MDA) level in parallel with GSTP-positive lesions. These results indicate that pre-existing fibrosis with the activated stellate cells accelerates the development of preneoplastic lesions in a CDAA diet model.

A recurrent nonrandom translocation (3;7)(q27;p12) associated with BCL-6 gene rearrangement in B-cell diffuse large cell lymphoma

Two cases of B-cell diffuse large cell lymphoma associated with the t(3;7)(q27;p12) and BCL-6 rearrangement are described. Cytogenetic studies revealed [case 1] 47,XY,t(3;7)(q27;p12),+12 and [case 2] 45,X,-Y,t(3;7)(q27;p12),del(6)(q21q25),+16,-21. The translocation of each case had a non-random chromosomal change involving a 3q27 locus associated with BCL-6 gene rearrangement identified by Southern blot analysis. Both cases involved multiple lymph nodes and extranodal regions, such as stomach and peritoneal cavity in case 1, extranodal retroperitoneal space, subcutis, probable liver, and colon in case 2. Chemotherapy provided only short survival after onset: 17 and 16 months, respectively. Altered expression of adhesion molecules CD44, CD54 (case 1) and CD11a and CD18 (case 2) may help to explain the poor outcome of these patients.

Three-dimensional reconstruction and measurement study of human eustachian tube structures: a hypothesis of eustachian tube function

Histologic sections from nine temporal bones with eustachian tubes (ETs) attached were analyzed with a computer-aided three-dimensional reconstruction method to determine the curvature and tilt of the ET and the anatomic relationships between the medial lamina of the ET cartilage, the levator veli palatini muscle (LVPM), and Rosenmüller's fossa. It was found that the ET is convex superomedially and is tilted medially. The LVPM is located inferolateral to the inferior margin of the medial lamina of the anterior ET cartilage. The LVPM is inferior to the medial lamina of the posterior ET cartilage. These findings suggest that the LVPM opens the anterior cartilaginous portion of the ET by rotating the medial lamina with increased dimension of the muscle body when it contracts. Rosenmüller's fossa extends along the ET with rich lymphoid tissues as far as approximately one half the total length of the ET and very close to the skull base.

Silencing of CYP1A1 expression in rabbits by DNA methylation

Unlike most experimental animals, treatment of adult rabbits with 3-methylcholanthrene (MC) does not induce the expression of the CYP1A1 gene. In this study, we show that DNA methylation plays one of the key roles in the suppression of CYP1A1 gene expression. S1 nuclease protection assay showed that the induction of CYP1A1 mRNA by MC occurred in rabbit kidney RK13 cells but not in rabbit lung R9ab cells, while aryl hydrocarbon receptor (AhR) and AhR nuclear translocator (Arnt) mRNAs were expressed in both cells at similar levels. Interestingly, the treatment of R9ab cells with a DNA demethylating agent, 5-aza-2'-deoxycitidine, resulted in the induction of the expression of the CYP1A1 gene by MC. The results indicate that DNA methylation is one of the factors involved in the loss of the MC-induced expression of the CYP1A1 gene. Thus, it seemed that the binding of the AhR/Arnt complex to the xenobiotic-responsive element (XRE) was inhibited by the hypermethylation of CpG dinucleotides within an XRE core sequence (5'-CGTG-3'). To explore this possibility, we compared the methylation status of XRE in R9ab cells with that in RK13 cells. A bisulfite sequence analysis using genomic DNAs from R9ab cells showed that the CpG site within XRE was highly methylated on both coding and non-coding strands. In contrast to this result, the hypomethylation of XRE was seen in RK13 cells. To examine whether or not the binding of the AhR/Arnt heterodimer to XRE is affected by the methylation status of XRE, a gel shift assay using a methylated XRE as a probe was carried out. As expected, the AhR/Arnt complex could not bind to the methylated XRE. From these results, we conclude that the cell type-specific transcription of the rabbit CYP1A1 gene is caused by DNA methylation.

Fulminant hepatitis complicated by small intestine infection and massive hemorrhage

A 34-year-old man diagnosed with fulminant hepatitis, caused by hepatitis B virus, and acute renal failure was referred to our hospital. After admission to the intensive care unit, the liver and renal failure were ameliorated. Melena requiring transfusion occurred during the course of his illness. Endoscopic examination demonstrated pseudomembranes, erosions, ulcers, and hemorrhage in the duodenum, the upper jejunum, and the terminal ileum, suggesting widespread lesions throughout the small intestine. Pseudomonas putida, Xanthomonas maltophilia, and Candida glabrata were cultured from ileal fluid. Candida glabrata was also detected in sputum, feces, and on an intravenous catheter tip. The patient was treated with amphotericin B and miconazole. The melena was ameliorated, but inflammation of the small intestine persisted. Although we had difficulty in treating the enteritis, the patient survived, and 1 year later colonoscopic examination demonstrated no abnormalities. The small intestine is a difficult site to examine, but endoscopic examination of this site is important when massive hemorrhage develops.

Histopathological features of a cochlear implant and otogenic meningitis in Mondini dysplasia

The temporal bones of a 6-year-old boy with a cochlear implant for profound hearing loss associated with Mondini dysplasia were studied histopathologically. Despite having severe Mondini dysplasia, he was able to detect sound with the implant. On histological examination of the temporal bone, he had more than 10000 spiral ganglion cells. Histopathological changes in the inner ear associated with the cochlear implant were minimal. Patients with severe Mondini dysplasia and profound hearing loss may, therefore, benefit from cochlear implantation. In the contralateral ear, the patient had suppurative labyrinthitis and meningitis associated with chronic otitis media. Histopathological evidence of inflammatory necrosis of the round window membrane was consistent with suppurative labyrinthitis secondary to otitis media.

Genoepidemiology and pathogenicity of hepatitis G virus in Japan

A recently discovered non-A non-B hepatitis virus has been designated hepatitis G virus (HGV). Blood contamination has been proposed as its mode of transmission. We studied the genoprevalence of HGV in Japanese people at high risk. HGV was identified in serum by a reverse-transcription polymerase chain reaction. HGV was detected in 16.0% of intravenous drug users (IDUs) (n = 25), 16.2% of those with tattoos (n = 37), 10.9% of IDUs with tattoos (n = 55), 5.7% of chronic hepatitis (CH)-C patients (n = 87), and in none of the CH-B (n = 50) or CH non-B non-C (n = 46) patients. Serum alanine aminotransferase (ALT) levels of those infected with HGV alone (n = 3) were all within normal range. In the patients with CH-C, serum ALT levels of those coinfected with HGV were similar to serum ALT levels of those without HGV infection. A phylogenetic tree of isolated HGV clones showed that the HGVs of these subjects bore only a distant-resemblance to clones reported from Africa and North America, and that variation in the phylogenetic index of HGV clones was small. These results suggest that HGV clones from different areas have genetic heterogeneity and that HGV causes no or mild hepatitis.

[Hyperglycemia and symmetrical proximal neuropathy in diabetes]

A 60-year-old woman, diagnosed as having a diabetic symmetrical proximal motor neuropathy, is presented. In March 1995, she was referred to us because of untreated diabetes mellitus since 1990. Insulin treatment during one month decreased her postprandial plasma glucose level from more than 400mg/dl to about 200mg/dl. Soon after the treatment, she noticed lower proximal limb weakness bilaterally. In several months, her weakness progressed as the fasting plasma glucose level was increased. Her muscle power gradually recovered when the plasma glucose level was normalized. We therefore suggest that metabolic changes related to hyperglycemia, rather than ischemic vascular changes, play an important role in the pathogenesis of a diabetic symmetrical proximal motor neuropathy.

Immunohistochemistry of lymphocytes and macrophages in human celloidin-embedded temporal bone sections with acute otitis media

Immunohistochemical analyses were used to investigate the distribution of lymphocytes and macrophages in routine human temporal bone sections obtained from a subject with acute suppurative otitis media. Primary antibodies specific for human CD3 and CD43 (T-lymphocytes), CD20 (B-lymphocytes), CD45 (leukocyte common antigen), and CD68 (macrophages) were used. As a pretreatment, the sections were soaked in antigen retrieval solution (saturated sodium hydroxide-methanol solution in methanol at a ratio of 1:3). A second antigen retrieval procedure (microwave treatment in 1% zinc sulfate) was also employed for identifying CD3-positive cells. Then the avidin-biotin-peroxidase complex technique was performed. Positive reactions to all antibodies but anti-CD68 were observed in the mucosa of the eustachian tube, tympanic cavity, and mastoid air cells. Particularly, cells positive to anti-CD3 or anti-CD43 were making a diffuse invasion upon the lamina propria. CD68-positive cells were scattered only in the effusion of mastoid air cells. These results suggest that the retrospective immunohistochemical study of archival temporal bone sections is a promising approach to investigate the pathogenesis of otitis media.

Construction, bacterial expression, and characterization of hapten-specific single-chain Fv and alkaline phosphatase fusion protein

We have designed and constructed a bacterial expression vector to produce a fusion protein of hapten-specific single-chain Fv (ScFv) and alkaline phosphatase (PhoA) in Escherichia coli. The ScFv gene was assembled using genes encoding the heavy and light chain variable domains of anti-NP (4-hydroxy-3-nitrophenyl acetyl) mouse monoclonal antibody. The ScFv gene was then fused to the 5' terminus of the E. coli PhoA coding region. The expressed fusion protein ScFv(NP)-PhoA was purified using an NP affinity column, and gel-filtration. Characterization of the fusion protein was then performed. The estimated molecular weight by gel filtration was approximately 151 kDa, suggesting the dimerization of the protein. Kinetic constants of ScFv(NP)-PhoA were calculated and compared with those of wild-type PhoA. The k(cat) values of ScFv(NP)-PhoA and wild-type PhoA were 103 (s(-1)) and 96.1 (s(-1)), respectively, showing that PhoA activity was somewhat increased by tethering the molecules. The equilibrium binding constant of ScFv(NP)-PhoA was determined using two different haptens, NP-capronate and NIP(3-iodo-4-hydroxy-5-nitrophenyl acetyl) by means of fluorescence quenching measurements. The obtained binding constants were 2.2 x 10(5) (M-1) for NP-capronate and 1.O x 10(6) (M(-1)) for NIP, respectively. No apparent difference in binding constants was seen between ScFv(NP) and ScFv(NP)-PhoA, showing that sufficient specificity and binding affinity were retained when ScFv(NP) was tethered to alkaline phosphatase. ScFv(NP)-PhoA can be used to detect nanogram concentrations of NP-BSA in ELISA without the use of chemically conjugated secondary antibodies.

Regulation of the "tetCD" genes of transposon Tn10

In addition to the genes involved in tetracycline resistance, the loop region of the composite transposon Tn10 contains two other known genes, tetC and tetD, whose functions are unclear. Using primarily a genetic approach, we examined tetCD gene expression and regulation. The tetC gene product, TetC, is a diffusible repressor of both tetC and tetD transcription. Despite an earlier claim by others, we do not detect induction of either tetC or tetD by tetracycline (Tc) or several of its analogs. Although the 5' ends of the tetC and tetD messages overlap due to transcription from convergent promoters, we find no evidence for anti-sense RNA control. The operator for the TetC repressor has been localized. We also demonstrate that transcription from the tetD promoter probably terminates within IS10-Right and does not apparently interfere with Tn10 or IS10-Right transposition or its regulation.

Narrowest (isthmus) portion of eustachian tube: a computer-aided three-dimensional reconstruction and measurement study

Nine normal human temporal bones from persons 16 to 88 years old were studied by computer aided three-dimensional reconstruction and measurement. The length of the eustachian tube (ET) lumen in three portions (from pharyngeal orifice to tympanic orifice: cartilaginous, junctional, and bony) averaged 23.6 +/- 4.3 mm, 3.0 +/- 1.9 mm, and 6.4 +/- 2.6 mm. The narrowest portion of the ET lumen was in the cartilaginous portion in all cases: 20.5 +/- 4.2 mm from the pharyngeal orifice and 3.1 +/- 1.6 mm from the pharyngeal margin of the junctional portion. The cross-sectional area of the narrowest portion was 0.65 +/- 0.2 mm2. The tendon of the tensor veli palatini muscle (TVPM) inserted into the lateral lamina in the narrowest portion of the ET lumen in five of nine cases. These results suggest that contraction of the TVPM opens the narrowest portion of the ET lumen to ventilate the middle ear and that this portion also plays a role in protecting the middle ear.

99mTc-HSA-D scintigraphy in the diagnosis of protein-losing gastroenteropathy due to secondary amyloidosis

Secondary amyloidosis frequently involves the gastrointestinal tract and may result in ulceration, hemorrhage, and protein-losing enteropathy. We report a patient with severe hypoalbuminemia in whom endoscopy revealed widespread ulceration of the small intestine. The protein-losing site was detected by 99mTc-diethylene triamine pentaacetic acid human serum albumin (99mTc HSA-D) scintigraphy. This evidence suggests that the ulcers and mucosal lesions associated with amyloidosis contribute to abnormal protein loss from the gastrointestinal tract.

Circular dichroism analysis of the interaction between the alpha and beta subunits in a killer toxin produced by a halotolerant yeast, Pichia farinosa

SMK toxin is a killer toxin produced by a halotolerant yeast, Pichia farinosa. It is a heterodimer consisting of alpha (63 aa) and beta (77 aa) subunits, between which no disulfide bond exists. The two subunits interact tightly with each other below pH 5. However, the subunits dissociate under neutral conditions, resulting in the aggregation of the alpha subunit and the concomitant loss of killer activity. CD spectral measurements showed that the secondary structure of the SMK toxin changes drastically in the pH range 5.1-5.5 and that after the dissociation of the subunits, the soluble beta subunit alone cannot take any secondary structure. It was also shown that the concentration of NaCl does not affect the secondary structure of the SMK toxin.

The novel acidophilic structure of the killer toxin from halotolerant yeast demonstrates remarkable folding similarity with a fungal killer toxin

BACKGROUND

Several strains of yeasts and fungi produce proteinous substances, termed killer toxins, which kill sensitive strains. The SMK toxin, secreted by the halotolerant yeast Pichia farinosa KK1 strain, uniquely exhibits its maximum killer activity under conditions of acidic pH and high salt concentration. The toxin is composed of two distinct subunits, alpha and beta, which tightly interact with each other under acidic conditions. However, they are easily dissociated under neutral conditions and lose the killer activity. The three-dimensional structure of the SMK toxin will provide a better understanding of the mechanism of toxicity of this protein and the cause of its unique pH-dependent stability.

RESULTS

Two crystal structures of the SMK toxin have been determined at 1.8 A resolution in different ionic strength conditions. The two subunits, alpha and beta, are jointly folded into an ellipsoidal, single domain structure belonging to the alpha/beta-sandwich family. The folding topology of the SMK toxin is essentially the same as that of the fungal killer toxin, KP4. This shared topology contains two left-handed split betaalphabeta motifs, which are rare in the other proteins. Many acidic residues are clustered at the bottom of the SMK toxin molecule. Some of the carboxyl sidechains interact with each other through hydrogen bonds. The ionic strength difference induces no evident structural change of the SMK toxin except that, in the high ionic strength crystal, a number of sulfate ions are electrostatically bound near the basic residues which are also locally distributed at the bottom of the toxin molecule.

CONCLUSIONS

The two killer toxins, SMK and KP4, share a unique folding topology which contains a rare structural motif. This observation may suggest that these toxins are evolutionally and/or functionally related. The pH-dependent stability of the SMK toxin is a result of the intensive interactions between the carboxyl groups. This finding is important for protein engineering, for instance, towards stabilization of the toxin molecule in a broader pH range. The present crystallographic study revealed that the structure of the SMK toxin itself is hardly affected by the ionic strength, implying that a high salt concentration affects the sensitivity of the cell against the toxin.

Crystallization and preliminary X-ray diffraction studies of a novel killer toxin from a halotolerant yeast Pichia farinosa

A killer toxin from a halotolerant yeast, Pichia farinosa strain KK1, was crystallized at high- and low-salt concentrations. Crystals from the high-salt solution belonged to the tetragonal space group P4(1)2(1)2 or P4(3)2(1)2, with unit-cell dimensions of a = b = 81.10, c = 118.46 A. The low-salt solution provided crystals that belonged to the same space group, with nearly same cell dimensions. Preliminary diffraction studies showed that the intensity distributions are significantly different between the two crystals. Both types of crystals contained either two or three molecules per asymmetric unit. They diffracted X-rays beyond 2.0 A resolution and were stable to X-ray irradiation.

[Suitable measure for medicines resulting from pharmacist-visit and assistance for a good treatment]

Our medication team, consists doctors, nurses, pharmacists, and other staffs, made an effort to satisfy our patients with medical treatment. We especially tried to guarantee patient rights. Pharmacists visited patients in September 1995, seeking to inform every patient about effects and side effects of medicines using the "Medicine Information Sheet" with samples. As a result, in one case now under treatment by medicine, he no longer needs it. Then, our medication team had a conference and his doctor changed his prescription. In another case, we found a symptom suspected to be a side effect of a medicine. We asked his doctor about it, and he stopped the medicine in question. His medical condition then became better. This resulted in a "suitable amount" of medicine. We are confident that this is also necessary for every patient under treatment at home, when a pharmacist visits his or her home and informs them about the effects and side effects of medicines, and assists them to assure good treatment.

Identification of regions in the human angiotensin II receptor type 1 responsible for Gi and Gq coupling by mutagenesis study

Previous mutagenesis studies of angiotensin II (Ang II) receptor type 1 (AT1) have focused on determining the regions responsible for Gq coupling using the rat AT1 receptor. We created human AT1 receptor mutants, expressed them in COS-7 cells, and identified the domains crucial for Gi coupling as well as for Gq coupling. Substitution of Asp125, Arg126, Tyr127, and Met134 by Gly, Gly, Ala, and Ala in the highly conserved sequence of the second intracellular loop in most G protein-coupled receptors provided a mutant AT1 receptor which lost the ability to couple to both Gq and Gi with no impairment in its binding to Ang II. A truncated mutant lacking the carboxyl terminal 50 residues was completely deficient in coupling to Gi, whereas it retained full ability to bind to Gq, in contrast to the rat AT1 receptor. These findings demonstrate that the cytoplasmic tail in the human AT1 receptor is the determinant of specific Gi coupling.