Developmental regulation of gene expression for the MPTP delta isoforms in the central nervous system and the immune system

MPTP delta is a murine transmembrane protein tyrosine phosphatase which has three isoforms, types A-C, differing in the structure of the extracellular regions. In this study, we examined MPTP delta isoform expression in the brain and the immune system at discrete developmental or differentiation stages. RT-PCR analysis demonstrated that another isoform, type D, is transcribed from the MPTP delta gene. In the brain, only type D was expressed until postnatal day 7 (P7), but after P14, all four isoforms were detected. In contrast, the spleen, thymus and all the hematopoietic cell lines examined express only types B and C isoforms. An in situ hybridization study showed that MPTP delta mRNA is diffusely expressed throughout the spleen, but its expression in the thymus is restricted to the medullary region.

Peculiar effect of urea on the interaction of type I collagen with heparin on chromatography

Type I collagen in phosphate-buffered saline (PBS) bound to a heparin-Sepharose column, while heat-treated type I collagen, denatured chains of alpha 1(I) and alpha 2(I), did not. Conformation-dependent association of type I collagen with heparin was further examined in various urea concentrations. The relative amount of bound fraction decreased in proportion to the concentration of added urea; from over 90% in the absence of urea to about 30% in 3 M urea, although circular dichroism spectrum of type I collagen was not changed by the presence of 4 M urea at 25 degrees C. In 2 M urea, the relative amount of bound fraction was about 50%. Rechromatography of the flow-through fraction or bound fraction of type I collagen in 2 M urea after lyophilization showed a similar pattern to that of the initial type I collagen solution in that about a half of either sample was recovered as bound fraction. This result indicated that the association potential of type I collagen with heparin appeared to have changed reversibly. The relative amount of bound fraction was little affected by the initial protein concentration, suggesting that intermolecular interaction between type I collagen molecules or the aggregate possibly resulting from the interaction is not important in the affinity with heparin. From these results, we suggest that triple-helical type I collagen molecules undergo reversible changes of conformation in urea solution between the conformation with heparin affinity and that without the affinity. In contrast, type V collagen or alpha1 (V) chain binds to heparin under the same conditions and therefore the conformational change of type V collagen in urea solution would not be discernible in terms of heparin affinity, even if the type V collagen molecules have altered conformation in urea, as is suggested for type I collagen.

Selective repression of growth-regulating cdk2, cyclin E and E2F1 genes in human cell senescence

Normal human diploid TIG-1 fibroblasts underwent replicative senescence around 64-68 population doubling levels (PDL) by the irreversible serum-unresponsive G1-growth arrest. Repression of growth-promoting genes was searched in this study. The RT-PCR and Western blot analyses have shown that in senescent TIG-1 cells at PDL64-67, cdk2 and cyclin E were selectively repressed at the mRNA and protein levels even after serum stimulation, and cdc2 and cyclin A were less repressed than cdk2 and cyclin E. Such a specific lack of cdk2 and cyclin E proteins correlated with unphosphorylation of the retinoblastoma gene product (pRB) in senescent cells. Transcription factor E2F1 was also completely repressed at the mRNA and protein levels in senescent TIG-1 cells. Middle-passage cells exhibited active expressions of all the above genes and pRB phosphorylation. Therefore, the present results have indicated the selective repressions of cdk2, cyclin E and E2F1 in senescent cells.

The relation between cubital tunnel syndrome and the elbow alignment

The authors reviewed forty-three surgically managed cases of cubital tunnel syndrome treated during the past twelve years. Surgery had been performed on thirty-one men and twelve women. Their average age was 46.8 years old. The etiology of cubital tunnel syndrome had been determined as follows: There were twenty-three cases of osteoarthritis of the elbow joint. There were four cases of isolated cubitus valgus deformity. There were three cases of isolated cubitus varus deformity. There were three cases of rheumatoid arthritis. One patient had sustained trauma to the cubital tunnel. In nine other patients there were various causes but no joint malalignment. The selection of the surgical technique for the correction of cubital tunnel syndrome was a function of the etiology of the condition. Cubital tunnel syndrome from osteoarthritis was surgically managed with a modified King technique. Ulnar neuropathy with a cubitus valgus deformity was managed with an ulnar nerve anterior transposition. Ulnar neuropathy with a cubitus varus deformity was managed with a neurolysis. The surgical outcome for cubital tunnel syndrome in patients with an angular deformity at the elbow frequently was not optimum. However, although some patients remained symptomatic, the majority of postoperative patients did obtain improved motor strength and conduction velocities. This confirmed the efficacy of surgical management regardless of the cubital tunnel syndrome etiology.

PCR analysis of the Y chromosome long arm in azoospermic patients: evidence for a second locus required for spermatogenesis

We analyzed DNA from 63 Japanese men with either azoospermia or severe oligospermia whose Y chromosomes were cytogenetically normal. A total of 16 loci were examined: 15 loci on the long arm between DYS7E and DYZ1, and the YRRM1 locus, a candidate gene for the azoospermic factor, AZF. One patient with a pericentric inversion of the Y chromosome was also included. We detected micro-deletions in ten individuals. The YRRM1 gene was involved in only three of them. The remaining seven patients showed deletion between DYS7C and DYS239 in common, indicating the presence of at least one additional gene, deletion of which causes azoospermia.

Erythema nodosum-like eruption in sarcoidosis

Two cases of sarcoidosis with tender, erythematous nodules on the legs are reported. The cutaneous lesions were clinically similar to those of erythema nodosum, but histologically showed non-caseating epithelioid granulomas. A review of 14 cases of this particular sarcoid eruption reported in Japan showed that 13 had ocular involvement as in our cases. In the light of the high frequency of ocular involvement, a skin biopsy should be considered in patients presenting with erythema nodosum-like eruptions situated on the legs.

Current seroepidemiological status of hepatitis A with a comparison of antibody titers after infection and vaccination

The overall prevalence of anti-hepatitis A virus antibodies was 49.6% in 385 inhabitants in Honda City, Japan in 1991. An approximately 50% prevalence rate occurred between 40 and 49 years of age. The prevalence of anti-HAV antibodies was significantly lower in 1991 than in 1982 in the age groups 20 to 29 years and 30 to 39 years (p < 0.01), suggesting there has been no significant HAV infection since 1982. In addition, anti-HAV antibody titers of sera from convalescent hepatitis. A patients were compared with those from seropositive healthy subjects and from healthy subjects following administration of a lyophilized inactivated hepatitis A vaccine or immune serum globulin. Titers after vaccine administration were considerably higher than after immune serum globulin and, although lower than those obtained after natural infection, should be sufficient for protection against hepatitis A virus.

Molecular cloning of a chicken lung cDNA encoding a novel protein kinase with N-terminal two LIM/double zinc finger motifs

Using the cDNA fragment of chicken c-sea receptor tyrosine kinase as a probe, we isolated from a chicken lung cDNA library overlapping cDNA clones encoding a novel protein kinase, which we termed LIM-kinase (LIMK). The predicted polypeptide of 642 amino acid residues contains remarkable structural features, composed of the N-terminal two tandemly arrayed LIM/double zinc finger motifs and the C-terminal unusual protein kinase domain. To our knowledge, a protein kinase containing the LIM motif in the molecule has not heretofore been described. The protein kinase domain of LIMK shares highly conserved residues with the known protein kinases, but LIMK is unique in that it contains the sequence DLNSHN in subdomain VIB and a short, highly basic insert sequence, which may function as a signal for nuclear localization, between subdomain VII and VIII in the protein kinase domain. Northern blot analysis revealed that the single species of LIMK mRNA of 3.8 kb is expressed predominantly in the lung, and faintly in the kidney, liver, brain, spleen, gizzard, and intestine. As the LIM motif is thought to be involved in protein-protein interactions by binding to another LIM motif, and is often present in the homeodomain-containing proteins involved in cell fate determination and in the oncogenic nuclear proteins (rhombotins), it is likely that LIMK is involved in developmental or oncogenic processes through interactions with these LIM-containing proteins.

Spontaneous production of interleukin-8 by human lung cancer cells and its augmentation by tumor necrosis factor alpha and interleukin-1 at protein and mRNA levels

A cell-to-cell interaction between tumors and host inflammatory cells is important for the subsequent cancer progression or regression. We examined the expression of interleukin-8 (IL-8) mRNAs by 9 human lung cancer cell lines and the influences of cytokines on IL-8 production and its gene expression. Substantial expressions of IL-8 gene were detected in 3 lung cancer cell lines (RERF-LC-OK, Lu-134-A-H, YO-88 cells). Moreover, 4 lung cancer cell lines (RERF-LC-MS, RERF-LC-OK, A549 and YO-88) were used to examine the effects of exogenous cytokines--interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF-alpha) and granulocyte-macrophage colony-stimulating factor--on IL-8 production by the cells at protein and gene levels. TNF-alpha and IL-1 beta significantly augmented the levels of mRNA expression for IL-8 and its production. These observations indicate that tumor-derived IL-8 may be important in recruiting inflammatory neutrophils and promoting interaction between lung cancer and inflammatory cells.

Brain-derived neurotrophic factor promotes differentiation of striatal GABAergic neurons

The influence of neurotrophins on GABAergic properties of developing striatal neurons was investigated both in vivo and in vitro. Brain-derived neurotrophic factor (BDNF) specifically elevated cellular GABA content in striatal culture without altering neuronal survival. Neurotrophin-5 produced a similar effect on GABA, but nerve growth factor and neurotrophin-3 had no effect. An increase in GABA content in the striatum was also observed following BDNF injections into the cerebroventricle of neonatal rats. The increase of GABA levels in culture mainly resulted from an increase in holoenzyme activity of the GABA synthetic enzyme glutamic acid decarboxylase (GAD) and elevation of GABA uptake activity. In BDNF-treated striatal cultures, the newly differentiated neurons extended elaborate neurites and exhibited strong GAD immunoreactivity. These alterations were presumably caused by the upregulation of mRNA encoding GAD67 and the neuronal GABA transporter GAT-1. BDNF treatment also promoted other phenotypic differentiation of striatal neurons: BDNF increased the frequency of parvalbumin-immunoreactive neurons and calbindin-immunoreactive neurons and neuropeptide content for neuropeptide Y and somatostatin. These observations suggest that neurotrophins may contribute to phenotypic differentiation of GABAergic neurons in the developing striatum.

Cholesterol sulfate, a novel activator for the eta isoform of protein kinase C

Activity of protein kinase C depends on the interaction with polar head-groups of two membrane lipids, i.e., phosphatidylserine and diacylglycerol. In the present study, we demonstrated a novel activation mechanism of the eta isoform of protein kinase C (nPKC eta), which is predominantly expressed in epithelial tissues in close association with epithelial differentiation. We found that the nPKC eta was activated by cholesterol sulfate, a metabolite of cholesterol formed during squamous differentiation. This activation was greater than that by phosphatidylserine plus phorbol ester; the Vmax for the activation by cholesterol sulfate was 3.6 times that by phosphatidylserine plus phorbol ester, while Kms were almost equal. In the presence of cholesterol sulfate, phorbol ester only weakly enhanced the activity of nPKC eta. Activation of nPKC eta by cholesterol sulfate was further demonstrated by autophosphorylation of the kinase molecule. However, the alpha and delta isoforms of protein kinase C were not activated by cholesterol sulfate. The present observation affords a new insight into a signal transduction pathway of squamous differentiation.

Phorbol ester-induced activation of a membrane-bound candidate pro-transforming growth factor-alpha processing enzyme

Transforming growth factor-alpha (TGF-alpha) is synthesized and transported to the cell surface as a membrane-anchored precursor (proTGF-alpha) that is converted to the soluble form by proteolytic cleavage. ProTGF-alpha cleavage is activated in response to tumor-promoting phorbol ester or to calcium ionophore. Mechanism(s) controlling conversion of the membrane-anchored precursor to the soluble TGF-alpha are unknown, and the responsible protease has not been identified. Using the fluorogenic substrate succinyl-Ala-Ala-Ala-4-methylcoumaryl-7-amide (Suc-Ala-Ala-Ala-MCA), containing the sequence similar to the cleavage sites for proTGF-alpha processing, we identified a putative candidate proTGF-alpha-converting enzyme in the membrane fractions of Chinese hamster ovary (CHO) cells. The enzyme activity was about 5-6-fold increased by exposure of the cells with phorbol ester or with calcium ionophore. The enzyme activity was released from the cells by trypsin added exogenously; hence, the activity probably locates on the outer surface of the cell membrane. The enzyme was partially purified from membranes of phorbol ester-treated CHO cells. The molecular mass of the enzyme was estimated to be about 84 kDa by gel filtration analysis. Inhibitor profile of the enzyme, including inhibition by serine protease inhibitors and no inhibition by elastatinal, coincides with that previously reported for proTGF-alpha cleavage activity on CHO cells. These findings suggest that the enzyme is a processing protease involved in the cleavage of proTGF-alpha and that induction of proTGF-alpha conversion by phorbol ester or by calcium ionophore can be attributed to activation of the processing protease. In the cell-free reconstitution system, the membrane-bound Suc-Ala-Ala-Ala-MCA-hydrolyzing enzyme from CHO cells was also activated by phorbol ester in the presence of the soluble fraction, ATP, and vanadate. Requirement of vanadate, an inhibitor for protein phosphatases, for activation of the enzyme in this system suggests that phosphorylation-dephosphorylation probably plays a key role in the regulated cleavage of proTGF-alpha.

Differential diagnosis of ovarian tumors by transvaginal color-pulse Doppler sonography

To investigate the clinical significance of transvaginal color-pulse Doppler sonography in ovarian tumors, 109 patients were examined at Nagoya University Hospital. Ultrasonographic patterns were classified and the levels of three circulating tumor markers, CA125, CA72-4, and CA19-9, were simultaneously evaluated. In differentiating benign and malignant ovarian tumors, transvaginal color-pulse Doppler and ultrasonographic pattern classification were superior to the tumor markers. Of 49 cases with benign pattern, 45 were benign (91.8%). Of 60 cases with malignant pattern, 24 (40%) were benign and 36 (60%) were malignant or borderline malignant. In this group color-pulse Doppler sonography was the most useful procedure, and sensitivity, specificity, and accuracy were 75.0, 79.2, and 76.7%, respectively. Menopausal status and site of the arterial wave form in the tumor were also important. Transvaginal color-pulse Doppler sonography was a reliable diagnostic method for differentiating ovarian tumors.

Cultured osteoblast synthesize nitric oxide in response to cytokines and lipopolysaccharide

Nitric oxide (NO) is generated from L-arginine by NO synthase. NO has been reported to be produced by a variety of cell types such as vascular endothelial cells, macrophages, neutrophils and articular chondrocytes. A recent report demonstrated that NO inhibits osteoclast (OC) function and, in this way, is critically associated with bone metabolism. In the present study we have studied NO synthesis by osteoblasts (OBs). OB cell line, MC3T3-E1, was cultured with the various cytokines for 72 hrs. Nitrite, a stable endproduct of cell-generated NO, in the culture supernatant was then determined by using a spectrophotometric method based on Griess reaction. IL-1 alpha increased nitrite release in a dose-dependent fashion and a significant enhancement (p < 0.01) was attained at 10 U/ml. OBs released 14.2 nmol/4.0 x 10(4) cells of nitrite after 72 hrs stimulation by 100 U/ml IL-1 alpha. In contrast IL-1 beta, TNF-alpha and INF-gamma failed to affect NO synthesis by MC3T3-E1. The results suggest that OBs produce NO in response to IL-1 alpha and OB-induced NO may play a role in OB-OC interaction in the inflammatory process.

Coinfection of hepatitis C virus in patients with chronic hepatitis B infection

Enzyme-linked immunosorbent assays for detecting antibodies against hepatitis C virus and the polymerase chain reaction were tested in 82 chronic hepatitis B surface antigen carriers for their accuracy in diagnosing patients coinfected with hepatitis B and C viruses. To clarify the role of each virus in chronic hepatitis, serologic assays against hepatitis B virus were also tested. Thirteen (14.9%), 14 (17.1%) and 15 (18.3%) patients were anti-HCV positive using C100 (HCV1), JCC, and a second generation test (HCV2), respectively. HCV RNA was detected by polymerase chain reaction in 9 of 18 anti-HCV-positive cases. Although HCV1 assays were not sufficient, either the JCC or HCV2 assay detected all polymerase chain reaction-positive cases. Fifteen of 18 specimens that were positive in at least one of the three ELISA were seronegative for the hepatitis B e antigen. As judged by HBV DNA polymerase activity, titers of hepatitis B surface antigen and immunoglobulin A antibody against hepatitis B core antigen (IgA anti-HBc), activity of hepatitis B virus replication and immune response against hepatitis B virus in patients with coinfection was decreased to the level of hepatitis B virus asymptomatic carriers. These results show that hepatitis C virus appears to be the primary cause of active hepatitis in most patients with hepatitis B and hepatitis C virus coinfection.

Synthesis and aldose reductase inhibitory activity of 2-substituted 6-fluoro-2,3-dihydrospiro[4H-1-benzopyran-4,4'-imidazolidine]-2',5'-dio nes

Optically active and racemic 2-substituted 6-fluoro-2,3-dihydrospiro[4H-1- benzopyran-4,4'-imidazolidine]-2',5'-diones were synthesized stereoselectively from (+)-, (-)-, and (+/-)-6-fluoro-3, 4-dihydro-4-oxo-2H-1-benzopyran-2-carboxylic acid [(+)-1, (-)-1, and (+/-)-1], respectively, for evaluation as new aldose reductase inhibitors. Among these compounds, the 2S,4S compounds were found to be more potent inhibitors of aldose reductase in vitro and in vivo than the corresponding 2R,4R enantiomers. The chloromethyl compound [(+)-5] showed highly potent activities in inhibiting cataract formation in the lenses and polyol accumulation in the sciatic nerve of rats.

Tachykinin-induced contractions in the circular muscle of guinea pig ileum

Actions of substance P (SP, 10(-9) to 10(-6) M), neurokinin A (NKA, 10(-9) to 10(-6) M) and neurokinin B (NKB, 10(-10) to 10(-6) M) in the circular muscle of guinea pig ileum were investigated in segment and strip preparations, in which methacholine produced similar contractions. In the segment preparations, three tachykinins produced repeatedly occurring twitch-like contractions. Their efficacies were similar with the same maximal contractions, but their potencies were different (NKB > NKA = SP). Latency (38 sec) was observed before the initiation of contractions in response to NKA, but not to SP or NKB. Atropine (10(-6) M) and tetrodotoxin (3 x 10(-7) M) did not affect NKA-induced contractions, but inhibited SP- and NKB-induced contractions; the dose-response curves for SP and NKB were rightwardly shifted by atropine. The treatment with atropine brought out latency in the responses for NKB. In the strip preparations, SP did not substantially induce concentrations, but NKA and NKB produced twitch-like contractions after latent periods of 28 and 36 sec, respectively. The efficacy of NKA was similar to that in segment preparations, while that of NKB was much lower in strip preparations. Unlike in segment preparations, atropine did not inhibit contractions induced by the two tachykinins in strip preparations. These results suggest that tachykinins induce contractions through myogenic and neurogenic mechanisms, the latter of which may be inoperative in strip preparations.