The EGP1 gene may be a positive regulator of protein phosphatase type 1 in the growth control of Saccharomyces cerevisiae

The Saccharomyces cerevisiae GLC7 gene encodes the catalytic subunit of type 1 protein phosphatase (PP1) and is required for cell growth. A cold-sensitive glc7 mutant (glc7Y170) arrests in G2/M but remains viable at the restrictive temperature. In an effort to identify additional gene products that function in concert with PP1 to regulate growth, we isolated a mutation (gpp1) that exacerbated the growth phenotype of the glc7Y170 mutation, resulting in rapid death of the double mutant at the nonpermissive temperature. We identified an additional gene, EGP1, as an extra-copy suppressor of the glc7Y170 gpp1-1 double mutant. The nucleotide sequence of EGP1 predicts a leucine-rich repeat protein that is similar to Sds22, a protein from the fission yeast Schizosaccharomyces pombe that positively modulates PP1. EGP1 is essential for cell growth but becomes dispensable upon overexpression of the GLC7 gene. Egp1 and PP1 directly interact, as assayed by coimmunoprecipitation. These results suggest that Egp1 functions as a positive modulator of PP1 in the growth control of S. cerevisiae.

[A case of post-traumatic arteriovenous fistula of the subclavian artery]

A 67-year-old woman was admitted to our hospital for a complete medical evaluation of a pulmonary nodule on a chest X-ray film, which was found during an annual check-up. A loud bruit was audible over the left chest and the supraclavicular region. Computerized tomography (CT) scan and magnetic resonance imaging revealed an arteriovenous fistula from a branch of the left subclavian artery into the paravertebral veins. Angiography disclosed that the arteriovenous fistula was fed by the left costocervical artery. Transarterial embolization of the arteriovenous fistula was done with 5 mechanical detachable coils and 2 micro coils. Postembolization angiography showed a marked decrease in blood flow and near-elimination of the arteriovenous fistula. The shrinkage of the arteriovenous fistula was also observed on CT scan. This patient had been in a traffic accident, and had been clinically well before the accident. Post-traumatic arteriovenous fistula was strongly suspected, because a pulmonary nodule on chest X-ray film and a bruit were found after a traffic accident.

Hepatocyte growth factor is involved in formation of osteoclast-like cells mediated by clonal stromal cells (MC3T3-G2/PA6)

Osteoclast formation from hemopoietic precursors has been shown to require the support of stromal cells in bone tissue. In this study, we demonstrated that hepatocyte growth factor (HGF) is one of the stromal cell-derived molecules responsible for osteoclast-like cell formation. For our experiments, we used a coculture system for osteoclastic cell formation and activation in which hemopoietic blast cells are cocultured with calvaria-derived stromal MC3T3-G2/PA6 (PA6) cells on dentine slices in the presence of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. Addition of anti-HGF neutralizing IgG to the cocultures inhibited the formation of osteoclastic cells and their dentine-resorbing activity. We detected a single 6.0-kb transcript for HGF in PA6 cells, and also recognized immunoreactive M(r) 81,000 and 88,000 forms of HGF in conditioned medium (CM) from PA6 cell cultures, the level of which reached 6 ng/ml. Both the CM and HGF stimulated the proliferation of blast cells synergistically with granulocyte-macrophage colony-stimulating factor, resulting in an increased number of osteoclast precursors that respond to 1,25(OH)2D3 that are tartrate-resistant acid phosphatase-positive multinucleate cells in stromal cell-free blast cell cultures in plastic wells. The effect of the CM was diminished by the addition of anti-HGF IgG. However, neither the CM nor HGF stimulated the formation of osteoclastic cells and pits on dentine slices in the absence of PA6 cells. These results suggest that although HGF cannot completely replace stromal cells, it is one of the paracrine mediators produced by stromal cells that act on proliferation of osteoclastic cell precursors.

Hyperactivity of central noradrenergic and CRF systems is involved in social isolation-induced decrease in pentobarbital sleep

The modulatory effects of the central noradrenergic and CRF systems on the pentobarbital-induced hypnotic activity were investigated in socially isolated mice. Pentobarbital-induced sleeping time decreased depending on the duration of isolation period and reached the minimum at 4 weeks after the isolation. The intermale aggressive behavior tested in isolated mice increased along with the decrease of hypnotic activity of pentobarbital. I.c.v. injection of CRF (corticotropin-releasing factor; 0.6-2.1 nmol) and i.p. injection of yohimbine (0.5-1 mg/kg), an alpha 2-adrenoceptor antagonist, significantly decreased the pentobarbital-induced sleeping time in group-housed but not in socially isolated mice while alpha-helical CRF9-41 (alpha hCRF; 3.3-6.5 nmol i.c.v.), a CRF antagonist, and clonidine (12.5-100 micrograms/kg i.p. and 7.5-15 nmol i.c.v.), an alpha 2-adrenoceptor agonist, recovered the hypnotic activity of pentobarbital decreased by social isolation to the level in group-housed mice without changing the activity observed in group-housed animals. alpha hCRF (6.5 nmol i.c.v.) significantly abolished the yohimbine (1 mg/kg i.p.)-induced decrease in the hypnotic activity of pentobarbital in group-housed mice. Propranolol (50-100 nmol i.c.v. and 5-10 mg/kg i.p.), a beta-adrenoceptor antagonist, and prazosin (5-10 nmol i.c.v. and 250-500 micrograms/kg i.p.), an alpha 1-adrenergic antagonist, significantly and dose-dependently recovered the hypnotic activity of pentobarbital in socially isolated mice to the level in group-housed mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Stimulation of DNA synthesis by mouse DNA helicase B in a DNA replication system containing eukaryotic replication origins

A number of DNA helicases have been isolated from mammalian cells, but their abilities to stimulate DNA replication accompanied with DNA unwinding have not been addressed so far. We constructed a model DNA replication system using the yeast autonomously replicating sequence (ARS) as the replication origin. In this system, SV40 T antigen as a DNA helicase assembles to the replication origin where the DNA duplex is unwound by torsional stress due to the negative supercoiling of template DNA, which leads to bidirectional DNA replication from the origin. We report here that DNA helicase B isolated from mouse FM3A cells can greatly stimulate DNA synthesis in this replication system in place of SV40 T antigen. DNA synthesis was dependent on the presence of single-stranded DNA binding protein (RP-A), DNA polymerase alpha/primase from mouse cells, and Escherichia coli DNA gyrase. DNA gyrase was required not only at elongation as a DNA swivelase but also at initiation to increase negative superhelical density of template DNA with the assistance of RP-A. A mammalian DNA fragment containing a replication initiation zone upstream of the c-myc gene as well as the yeast ARS fragment acted as a cis-element in this system using DNA helicase B. Both DNA helicase B and SV40 T antigen have the ability to extensively unwind the template DNA in the presence of RP-A and DNA gyrase, which may be crucial for stimulation of DNA synthesis in this system.

Effect of thielocin A1 beta on bee venom phospholipase A2-induced edema in mouse paw

Several investigators have reported that inactivation of secretory phospholipase A2 purified from bee venom with p-bromophenacyl bromide, an irreversible inhibitor, before injection resulted in attenuation of the subsequent inflammatory reaction in the mouse paw edema model. Recently, thielocin A1 beta, a novel secretory phospholipase A2 inhibitor from fungi, was found to suppress histamine release from mast cells stimulated with secretory phospholipase A2. These observations led us to examine the effect of thielocin A1 beta against secretory phospholipase A2-induced paw edema. Thielocin A1 beta inhibited bee venom phospholipase A2 in a dose-dependent manner (IC50 = 1.4 microM). In addition, the inhibition of bee venom phospholipase A2 was noncompetitive (Ki = 0.57 microM) and reversible. Subplantar injection of bee venom phospholipase A2 produced a rapid but transient edematous response. Coinjection of thielocin A1 beta (1 microgram/paw) with bee venom phospholipase A2 resulted in a 44.7 +/- 4.6% reduction of edema formation. This anti-edema action was not enhanced by cyproheptadine (antihistamine/antiserotonin). These results suggest that thielocin A1 beta shows edema-reducing activity via inhibition of the phospholipase A2 activity which participates in histamine release by mast cells.

Induction of transforming growth factor beta 1 and its receptors during all-trans-retinoic acid (RA) treatment of RA-responsive human neuroblastoma cell lines

Recent work on a variety of normal and malignant cell lines has shown that induction and secretion of biologically active TGF-beta may occur after exposure to all-trans-retinoic acid (RA), coincident with decreased growth rate and/or differentiation. This study evaluates the expression and regulation of transforming growth factor beta (TGF-beta) and its receptors during RA-induced cell growth arrest and induction of differentiation in the RA-sensitive human neuroblastoma cell line SMS-KCNR and the RA-resistant neuroblastoma cell line SK-N-AS. RA treatment of SMS-KCNR cells results in a 40-fold increase in TGF-beta 1 mRNA after 4 days of RA, a dose-dependent increase in TGF-beta 1 secretion, an increase in types I (TBRI) and III (TBRIII) TGF-beta receptor proteins, and an increase in type II TGF-beta receptor (TBRII) mRNA coincident with RA-responsiveness of the cells. However, in the RA-resistant line SK-N-AS, TGF-beta 1 is constitutively secreted at levels that are unchanged after RA treatment, and although TBRI and TBRIII mRNA is expressed in untreated SK-N-AS cells, levels of TBRI and TBRIII protein and TBRII mRNA decrease after RA treatment. Thus, in RA-sensitive neuroblastoma cells, RA treatment may result in the induction of a negative autocrine TGF-beta 1 growth regulatory loop. These results suggest the hypothesis that: (a) induction of a TGF-beta 1 negative autocrine growth loop may be a necessary component for RA-responsiveness of neuroblastoma cells in vivo; and (b) the inability to induce or maintain this TGF-beta 1 negative autocrine growth loop may be a mechanism of RA resistance in neuroblastoma.

Synergistic effects of insulin-like growth factor II (IGF-II) with leukemia inhibiting factor (LIF) on establishment of rat pluripotential cell lines

To examine effects of IGF-II on establishment of pluripotential diploid cells from rat embryos, we cultured blastocysts in medium containing mouse LIF with or without IGF-II. Combination of mouse LIF (5,000 units/ml) and rat IGF-II (100 ng/ml) promoted growth of inner cell mass (ICM) and was effective for establishment of pluripotential cell lines derived from the ICM. The cell lines indicated colony forms different from the rat ES cell lines. However, they showed morphological alteration to adult-like tissue cells, formed embryoid body in suspension culture, and thus, seemed to retain a pluripotent characteristics. The rat IGF-II is useful for establishing of pluripotential cells efficiently.

Congenital ossification of the stapedius tendon: diagnosis with CT

PURPOSE

To describe the features of congenital ossification of the stapedius tendon at thin-section computed tomography (CT).

MATERIALS AND METHODS

Thin-section CT scans, clinical records, and surgical findings were retrospectively evaluated in nine ears of five patients with surgically proved congenital ossification of the stapedius tendon. Thin-section CT scans of 50 control ears were also reviewed.

RESULTS

On thin-section CT scans, a linear area of soft-tissue attenuation was demonstrated between the monopod stapes and the pyramidal eminence (nine ears), as well as thickening of the stapes footplate (two ears). In the 50 control ears, the normal stapes tendon was not clearly seen on thin-section CT scans.

CONCLUSION

At CT, a linear area of soft-tissue attenuation that extends from the pyramidal eminence to the monopod stapes is suggestive of congenital ossification of the stapedius tendon or a bony bar adjacent to it.

Recurrent primary central nervous system lymphoma mimicking neurodegenerative disease--an autopsy case report

A 42-year-old female presented with recurrent primary central nervous system lymphoma mimicking the roentgenographic appearance of diffuse brain degeneration. Betamethazone was administered, but her condition worsened. Biopsy of a swollen neck lymph node demonstrated lymphoma cells. Computed tomography and magnetic resonance (MR) imaging showed no contrast-enhanced lesions. T2-weighted MR imaging revealed diffuse, high intensity areas in the white matter of the bilateral cerebrum, basal ganglia, and brainstem. Despite chemotherapy for systemic lymphoma, she died of respiratory arrest. Histological examination of autopsy specimens showed diffuse infiltration of lymphoma cells in the perivascular space of the cerebral cortex, but little neovascularization. The absence of contrast enhancement may have been due to preservation of the blood-brain barrier. Histological confirmation of roentgenographic findings of brain degeneration is important in patients treated for primary central nervous system lymphoma.

Low level of immunoglobulin G2a subclass correlates with a deficiency in T helper cell function in LEC mutant rats

Long-Evans Cinnamon (LEC) rats bear a congenital deficiency in CD4+8- thymocytes and consequently a deficiency in helper T cell function. This mutation is caused by a single recessive gene referred to as thid (T helper immunodeficiency). It has been reported that rat immunoglobulin(Ig) G2a subclass is a counterpart of the mouse IgG1. Serum IgG2a levels in LEC rats were ten-fold lower than those of normal rats. To identify a cause of low IgG2a levels in LEC rats, we made backcross rats, (F344 x LEC)F1 x LEC, and examined linkage to the thid mutation. The serum IgG2a levels of rats showing thid/thid phenotype were much lower than those of rats showing +/thid phenotype. This indicates that the thid mutation correlates with low level of IgG2a subclass. Furthermore, LEC rat B cells were shown to secret IgG2a normally when these were stimulated with LPS and IL-4, suggesting that a cause of low level of IgG2a was due to defect of T cell function but not due to B cell disfunction in LEC rats. These results confirm the idea that T-helper (Th) function is necessary for the class switch to IgG2a subclass in rats.

Salfredins, new aldose reductase inhibitors produced by Crucibulum sp. RF-3817. I. Fermentation, isolation and structures of salfredins

New inhibitors of aldose reductase, designated salfredins A3, A4, A7, C1, C2, C3 and B11, were isolated from the fermentation broth of Crucibulum sp. RF-3817 by successive purification procedures of solvent extraction, silica gel column chromatographies and reverse-phase HPLC. Their structures were established by spectroscopic methods, including UV, SI-MS and NMR. The structures of salfredins A4 and B11 were confirmed by X-ray crystallographic analysis.

Hepatocyte growth factor/scatter factor modulates cell motility, proliferation, and proteoglycan synthesis of chondrocytes

Hepatocyte growth factor/scatter factor (HGF/SF) is a multifunctional growth factor that promotes proliferation, motility, and morphogenesis in epithelial cells. Recently the HGF receptor, c-met protooncogene product, has been shown to be expressed in developing limb buds (Sonnenberg, E., D. Meyer, M. Weidner, and C. Birchmeiyer, 1993. J. Cell Biol. 123: 223-235), suggesting that some populations of mesenchymal cells in limb buds respond to HGF/SF. To test the possibility that HGF/SF is involved in regulation of cartilage development, we isolated chondrocytes from knee joints and costal cartilages of 23-d embryonic and 4-wk-old rabbits, and analyzed the effects of HGF/SF on migration and proliferation of these cells. We found that HGF/SF stimulated migration of cultured articular chondrocytes but did not scatter limb mesenchymal fibroblasts or synovial fibroblasts in culture. HGF/SF also stimulated proliferation of chondrocytes; a maximum three-fold stimulation in DNA synthesis was observed at the concentration of 3 ng/ml of HGF/SF. Moreover, HGF/SF had the ability to enhance proteoglycan synthesis in chondrocytes. The responsiveness of chondrocytes to HGF/SF was also supported by the observation that they expressed the HGF/SF receptor. Addition of the neutralizing antibody to rat HGF/SF affected neither DNA synthesis nor proteoglycan synthesis in rat chondrocytes, suggesting a paracine mechanism of action of HGF/SF on these cells. In situ hybridization analysis showed that HGF/SF mRNA was restrictively expressed in the areas of future joint regions in developing limb buds and in the intercostal spaces of developing costal cartilages. These findings suggest that HGF/SF plays important roles in cartilage development through its multiple activities.

Inhibitory effect of alkaloids extracted from the stem bark of Hunteria zeylanica on 5-lipoxygenase activity in vitro

The effects of alkaloid extract from the stem bark of Hunteria zeylanica Gard. (H. zeylanica) on the activities of cyclooxygenase and 5-lipoxygenase in A23187-stimulated rat mast cells were investigated. H. zeylanica alkaloid extract (0.3-300 micrograms/ml) inhibited leukotriene C4 (LTC4) production by 5-lipoxygenase in a concentration-dependent manner and it blocked the production by 50% at 300 micrograms/ml. On the other hand, the extract had no effect on prostaglandin D2 (PGD2) production by cyclooxygenase. Neither (-)-eburnamine nor pleiomutinine, major constituents of H. zeylanica alkaloid extract, inhibited the production of PGD2 and LTC4 in the A23187-stimulated mast cells. The inhibition of arachidonic acid metabolism via 5-lipoxygenase pathway may be due to minute amounts of other components as stated in the Discussion.

Cyclosporin A is a substance P (tachykinin NK1) receptor antagonist

The immunosuppressive cyclic undecapeptide, cyclosporin A, inhibited the binding of [125I]substance P to tachykinin NK1 receptors expressed by human IM-9 lymphoblastoid cells, U-373 MG human astrocytoma cells and guinea pig lung parenchyma with IC50 values of 425 +/- 58, 783 +/- 180, and 784 +/- 163 nM respectively. The dihydro derivative of cyclosporin A (dihydro-cyclosporin A) was an equally effective inhibitor, but the O-acetylated derivative (cyclosporin A-OAc) was 3-4 fold less potent. The cyclosporin compounds also inhibited [125I]neurokinin A binding to human NK2 receptors with potencies slightly less than at NK1 sites. In contrast, they were 8-20-fold less effective inhibitors of [125I]MePhe7-neurokinin B binding to guinea pig NK3 receptors (p < 0.001). Thus, the cyclosporin A compounds showed selectivity for NK1 and NK2 receptors. The structure-activity pattern for the effects of cyclosporin A compounds at tachykinin receptors differs from the pattern previously described for their immunosuppressive activity. All three compounds inhibited substance P induced interleukin-6 (IL-6) secretion from U-373 MG astrocytoma cells with potencies similar to their NK1 receptor binding affinities. In addition, cyclosporin A blocked substance P induced phosphatidylinositol (PI) turnover in U-373 MG cells without blocking the corresponding response to histamine. This novel pharmacological profile of the cyclosporin A compounds as NK1 receptor antagonists does not appear to correlate with other known in vitro cyclosporin A functions.

Point mutation of the somatostatin receptor 2 gene in the human small cell lung cancer cell line COR-L103

The effect of somatostatin (SS) on adrenocorticotrophic hormone (ACTH) secretion from COR-L103 cells derived from a human small cell lung carcinoma was examined. SS at 1 microM had no effect on ACTH secretion from the cells on either short-term or long-term incubation. Studies by the reverse transcription-polymerase chain reaction (RT-PCR) showed that mRNA transcripts of the somatostatin receptor (SSTR) 2, SSTR3 and SSTR4 genes were present in COR-L103 cells. Extra bands were obtained by PCR-single strand conformation polymorphism (SSCP) analysis of the SSTR2 gene Sequence analysis of the SSTR2 gene demonstrated one point mutation in codon 188 of TGG for tryptophan to TGA for a stop codon causing loss of 182 C-terminal amino acid residues of SSTR2. The nucleotide sequences of the SSTR3 and SSTR4 genes in COR-L103 cells were normal. Binding studies using 125I-Tyr11-SS-14 showed specific affinity binding sites on COR-L103 cells and mouse pituitary tumor AtT-20 cells. Octreotide acetate suppressed the binding of 125I-Tyr11-SS-14 to these two cell lines, but the Kd of COR-L103 cells (160 nM) was 60-fold higher than that of AtT-20 cells (2.6 nM). Affinity cross-linking studies using 125I-Tyr11-SS-14 gave three bands of 72 KDa, 55 KDa and 32 KDa from AtT-20 cells, but only two bands of 55KDa and 32kDa from COR-L103 cells. These findings suggest that SSTR2 is not expressed in the plasma membranes of COR-L103 cells due to a point mutation, but that this may have no influence on the effect of SS on ACTH secretion.

Replication factor encoded by a putative oncogene, set, associated with myeloid leukemogenesis

DNA replication of the adenovirus genome complexed with viral core proteins is dependent on the host factor designated template activating factor I (TAF-I) in addition to factors required for replication of the naked genome. Recently, we have purified TAF-I as 39- and 41-kDa polypeptides from HeLa cells. Here we describe the cloning of two human cDNAs encoding TAF-I. Nucleotide sequence analysis revealed that the 39-kDa polypeptide corresponds to the protein encoded by the set gene, which is the part of the putative oncogene associated with acute undifferentiated leukemia when translocated to the can gene. The 41-kDa protein contains the same amino acid sequence as the 39-kDa protein except that short N-terminal regions differ in both proteins. Recombinant proteins, which were purified from extracts of Escherichia coli, expressing the proteins from cloned cDNAs, possessed TAF-I activities in the in vitro replication assay. A particular feature of TAF-I proteins is the presence of a long acidic tail in the C-terminal region, which is thought to be an essential part of the SET-CAN fusion protein. Studies with mutant TAF-I proteins devoid of this acidic region indicated that the acidic region is essential for TAF-I activity.

Differential tubulogenic and branching morphogenetic activities of growth factors: implications for epithelial tissue development

At least two kidney epithelial cell lines, the Madin-Darby canine kidney (MDCK) and the murine inner medullary collecting duct line mIMCD-3, can be induced to form branching tubular structures when cultured with hepatocyte growth factor (HGF) plus serum in collagen I gels. In our studies, whereas MDCK cells remained unable to form tubules in the presence of serum alone, mIMCD-3 cells formed impressive branching tubular structures with apparent lumens, suggesting the existence of specific factors in serum that are tubulogenic for mIMCD-3 cells but not for MDCK cells. Since normal serum does not contain enough HGF to induce tubulogenesis, these factors appeared to be substances other than HGF. This was also suggested by another observation: when MDCK cells or mIMCD-3 cells were cocultured under serum-free conditions with the embryonic kidney, both cell types formed branching tubular structures similar to those induced by HGF; however, only in the case of MDCK cells could this be inhibited by neutralizing antibodies against HGF. Thus, the embryonic kidney produces growth factors other than HGF capable of inducing tubule formation in the mIMCD-3 cells. Of a number of growth factors examined, transforming growth factor alpha (TGF-alpha) and epidermal growth factor (EGF) were found to be tubulogenic for mIMCD-3 cells. Whereas only HGF was a potent tubulogenic factor for MDCK cells, HGF, TGF-alpha, and EGF were potent tubulogenic factors for mIMCD-3 cells. Nevertheless, there were marked differences in the capacity of these tubulogenic factors to induce tubulation as well as branching events in those tubules that did form (HGF >> TGF-alpha > EGF). Thus, at least three different growth factors can induce tubulogenesis and branching in a specific epithelial cell in vitro (though to different degrees), and different epithelial cells that are capable of forming branching tubular structures demonstrate vastly different responses to tubulogenic growth factors. The results are discussed in the context of branching morphogenesis during epithelial tissue development.

Abnormal CD45RC expression and elevated CD45 protein tyrosine phosphatase activity in LEC rat peripheral CD4+ T cells

LEC rats are known to show a maturational arrest in the development of CD4+8+ to CD4+8- cells in the thymus. Despite the blockade of maturation of CD4+8-thymocytes, CD4+ T cells were observed in peripheral lymphoid organs, and these cells exhibit a defect in interleukin-2 (IL-2) production upon concanavalin A (Con A) stimulation. Although peripheral CD4+ cells in normal rat highly expressed CD45RC (CD45RChigh), the level of CD45RC expression was low (CD45RClow) in LEC rat peripheral CD4+ cells. However, CD4+ cells from both strains highly expressed CD45 when those cells were stained by pan-CD45 mAb, suggesting that LEC rat CD4+ cells are deficient in expression of the CD45RC isoform, but not of CD45 molecules. When backcross rats from (F344 x LEC)F1 x LEC were examined, the phenotype for CD45 expression pattern in CD4+ cells was clearly correlated with IL-2 production level in response to Con A stimulation. Thus, CD45RClow cells exhibit a defect in IL-2 production, while CD45RChigh cells show normal IL-2 production. Protein tyrosine phosphatase (PTPase) activity in the membrane fraction of LEC rat CD4+ cells was threefold higher than that of normal rat CD4+ cells. Con A stimulation led to an increase in tyrosine phosphorylation levels, especially 100- and 40-kDa proteins, in normal rat CD4+ cells. In LEC rat CD4+ cells, however, the level of tyrosine phosphorylation in those proteins were very low. These results suggest that an elevated CD45 PTPase activity is responsive for a defect in IL-2 production in LEC rat peripheral CD4+ T cells.

Decreased expression of the GLUT4 glucose transporter protein in adipose tissue during pregnancy

Insulin resistance involves impaired activities of the glucose transport system in insulin target tissues. We therefore investigated the GLUT4 glucose transporter protein in adipose tissues from the pregnant women with normal glucose tolerance and from women with gestational diabetes mellitus, and compared these to nonpregnant women. Three groups of women were studied: nonpregnant women with normal glucose tolerance (N = 6), pregnant women with normal glucose tolerance (N = 6, gestational week 38.0 +/- 0.3), and pregnant women with gestational diabetes mellitus (N = 3, gestational week 38.6 +/- 0.3). The abdominal subcutaneous adipose tissues obtained from each group were subjected to analysis of the GLUT4 glucose transporter protein. The presence of the GLUT4 glucose transporter protein in the three groups was quantitatively determined by Western blot analysis of detergent-soluble adipose tissue extracts using anti-GLUT4 antibody. GLUT4 glucose transporter protein concentration in the adipose tissue of pregnant women were significantly lower than that in nonpregnant women, and this difference was more profound in women with gestational diabetes mellitus. We demonstrated that the content of GLUT4 protein was decreased in adipose tissue from normal pregnancy compared to nonpregnant women.

A carrier of Duchenne muscular dystrophy with dilated cardiomyopathy but no skeletal muscle symptom

A 29-year-old female developed dilated cardiomyopathy at 20 years of age but with no muscle symptoms. Her 2-year-old son with Duchenne muscular dystrophy (DMD)_had no demonstrable deletion in the dystrophin gene, but all fibers except for 5% 'revertant' fibers in a muscle biopsy specimen had no dystrophin. Both skeletal and cardiac muscle biopsy specimens from the mother showed a mosaic distribution of dystrophin-positive and -negative fibers, and so she was diagnosed as being a manifesting carrier of DMD. We conclude that, when one encounters a female patient with idiopathic cardiomyopathy with a high serum creatine kinase level, the suspicion of her being a manifesting DMD carrier should be ruled out.

Role of vasogenic edema and tissue cavitation in ischemic evolution on diffusion-weighted imaging: comparison with multiparameter MR and immunohistochemistry

PURPOSE

To examine the mechanisms of further evolution that occurs from the early to late phase after initial changes in diffusion-weighted imaging after cerebral ischemia.

METHODS

Sprague-Dawley rats were subjected to middle cerebral artery occlusion. Diffusion-, proton density-, T1- and T2-weighted imaging were performed on days 0, 2, and 6. Histologic examination (IgG, glial fibrillary acidic protein, and cresyl violet staining) was done after scanning.

RESULTS

Apparent diffusion coefficients (ADCs) in the ischemic hemisphere were significantly decreased on day 0. Thereafter, ADCs increased over time and became significantly higher than the contralateral side by day 6. Changes in basal ganglia occurred more rapidly than in cortex. Proton density-, T1-, and T2-weighted scans showed maximal changes on day 2. From day 0 to day 2, there are significant correlations between changes in ADC and changes in T1-weighted signals and T2-weighted signals. Histologic exam showed early neuronal injury on day 0, intense gliotic activity and protein leakage associated with infarction and edema on day 2, and cavitation in severely infarcted areas on day 6.

CONCLUSION

After initial reduction of ADC, the subsequent increase in ADC values on day 2 may be associated with vasogenic edema and cell lysis. Later elevations in ADC may be related to cavitation of infarcted tissue.

Lymphocytic hypophysitis: case report

We report a rare case of lymphocytic hypophysitis in a 52-year-old man who presented with a combination of hypopituitarism and diabetes insipidus. Magnetic resonance imaging with a contrast medium revealed an expanding sellar mass and thickening of the pituitary stalk with homogeneous enhancement. These findings may be useful in differentiating lymphocytic hypophysitis from pituitary adenoma. The unique clinical and radiological features of this case are discussed.

Circumferential Peyronie's disease involving both the corpora cavernosa

An extraordinary form of Peyronies disease is reported. The patient was a 52 year old male, who died of a malignant thymoma with multiple bone metastasis, extensive pleural carcinomatosis of the left lung and some metastatic nodules in the liver and the mesenterium. At autopsy, the proximal and middle portions of the penis were very hard. Macroscopically, the entire tunica albuginea of both the corpora cavernosa was markedly thickened, 2-4 mm; and calcified. Microscopically, the tunica albuginea showed extensive hyaline degeneration, calcification and ossifying foci with osteoblasts and osteoclasts. Inflammatory cells were frequently found beneath the thickened tunica albuginea. In the corpus cavernosum, cavernous arteries showed marked intimal thickening and medial muscular degeneration with a few inflammatory cells. Smooth muscles of the stroma were extensively atrophic and degenerative, and some of them were infiltrated with a few inflammatory cells. In the corpus spongiosum, the tunica albuginea was not thickened, but the smooth muscle in the stroma was atrophic and degenerative and a few inflammatory cells were also found. Surprisingly, there was no Littrés gland around the urethra. In Peyronies disease, the dorsal part of the penis is usually involved, and less frequently lateral or ventral sites are involved. The circumferential involvement of both the corpora cavernosa has not been reported until now, as far as the authors know.