Regulation of cyclin D1 by calpain protease

Cyclin D1, a critical positive regulator of G1 progression, has been implicated in the pathogenesis of certain cancers. Regulation of cyclin D1 occurs at the transcriptional and posttranscriptional level. Here we present evidence that cyclin D1 levels are regulated at the posttranscriptional level by the Ca2+-activated protease calpain. Serum starvation of NIH 3T3 cells resulted in rapid loss of cyclin D1 protein that was completely reversible by calpain inhibitors. Actinomycin D and lovastatin induced rapid loss of cyclin D1 in prostate and breast cancer cells that was reversible by calpain inhibitors and not by phenylmethylsulfonyl fluoride, caspase inhibitors, or lactacystin, a specific inhibitor of the 26 S proteasome. Treatment of intact NIH 3T3, prostate, and breast cancer cells with a calpain inhibitor dramatically increased the half-life of cyclin D1 protein. Addition of purified calpain to PC-3-M lysates resulted in Ca2+-dependent cyclin D1 degradation. Transient expression of the calpain inhibitor calpastatin increased cyclin D1 protein in serum-starved NIH 3T3 cells. Cyclins A, E, and B1 have been reported to be regulated by proteasome-associated proteolysis. The data presented here implicate calpain in cyclin D1 posttranslational regulation.

The Arabidopsis deetiolated2 mutant is blocked early in brassinosteroid biosynthesis

The Arabidopsis DEETIOLATED2 (DET2) gene has been cloned and shown to encode a protein that shares significant sequence identity with mammalian steroid 5 alpha-reductases. Loss of DET2 function causes many defects in Arabidopsis development that can be rescued by the application of brassinolide; therefore, we propose that DET2 encodes a reductase that acts at the first step of the proposed biosynthetic pathway--in the conversion of campesterol to campestanol. Here, we used biochemical measurements and biological assays to determine the precise biochemical defect in det2 mutants. We show that DET2 actually acts at the second step in brassinolide biosynthesis in the 5 alpha-reduction of (24R)-24-methylcholest-4-en-3-one, which is further modified to form campestanol. In feeding experiments using 2H6-labeled campesterol, no significant level of 2H6-labeled campestanol was detected in det2, whereas the wild type accumulated substantial levels. Using gas chromatography-selected ion monitoring analysis, we show that several presumed null alleles of det2 accumulated only 8 to 15% of the wild-type levels of campestanol. Moreover, in det2 mutants, the endogenous levels of (24R)-24-methylcholest-4-en-3-one increased by threefold, whereas the levels of all other measured brassinosteroids accumulated to < 10% of wild-type levels. Exogenously applied biosynthetic intermediates of brassinolide were found to rescue both the dark- and light-grown defects of det2 mutants. Together, these results refine the original proposed pathway for brassinolide and indicate that mutations in DET2 block the second step in brassinosteroid biosynthesis. These results reinforce the utility of combining genetic and biochemical analyses to studies of biosynthetic pathways and strengthen the argument that brassinosteroids play an essential role in Arabidopsis development.

Bronchiolitis in adults: pathology and imaging

The most common high resolution CT (HRCT) findings of bronchiolitis are centrilobular nodules and branching linear structures in the secondary pulmonary lobules or areas of air trapping. These findings can be helpful in suggesting the presence of bronchiolitis. However, they are nonspecific because there are overlapping features among various kinds of bronchiolitis. Bronchiolar or peribronchiolar inflammation appears as centrilobular nodule, while bronchiolectasis filled with secretions manifests with branching linear structure on HRCT. Air trapping is secondary to bronchiolitis. Proliferative bronchiolitis with the findings of patchy areas of consolidation or ground-glass opacity can be distinguished from other bronchiolitis. Mineral dust-induced bronchiolitis and peribronchiolar lesions in sarcoidosis present with perilymphatic (centrilobular plus perilobular) micronodules in the secondary pulmonary lobule. Bronchiolitis in hypersensitivity pneumonia appears with poorly defined centrilobular nodules, associated with ground-glass opacity and air trapping.

CT and US of the pancreas

The diagnostic capabilities of pancreatic imaging continue to improve with technological advancements in computed tomography (CT), ultrasound (US), and magnetic resonance imaging (MRI). To update the practicing radiologist, this article summarizes the current literature on pancreatic imaging, with particular emphasis on CT and US. Pertinent clinical considerations of the disease entities are included, along with illustrative material from the authors' experience.

Relationship of transforming growth factor beta 1 to angiogenesis in gastric carcinoma

Transforming growth factor-beta (TGF-beta) comprises a group of multifunctional regulatory proteins, whose effects include angiogenesis. The expression of TGF-beta 1 in gastric carcinomas (70 cases) has been determined and related to pathological features and microvessel count by immunohistochemical staining for TGF-beta 1 and Factor VIII related antigen. Prominent reactivity for TGF-beta 1 was associated with the depth of invasion (r = 0.2; p < 0.05) and increased microvessel count (r = 0.5; p < 0.05). Also, the microvessel count had a significant correlation with invasiveness (r = 0.34; p < 0.05) and lymph node metastasis (r = 0.28; p < 0.05). These findings indicate that TGF-beta 1 may have a role in tumor invasion and angiogenesis.

Seasonal variations in integumental glycoconjugates of Rana rugosa

BACKGROUND

Although environmental conditions can influence the expression of glycoconjugates (GCs) in the epidermis and cutaneous gland of amphibians, seasonal features regarding GCs in frogs have rarely been studied. In the present study, we report the seasonal variations of the integumental GCs in Rana rugosa.

METHODS

GCs were investigated at the light microscopic level using conventional and lectin histochemistry.

RESULTS

During the pre- through posthibernating periods, stronger periodic acid-Schiff (PAS)-positive GCs were observed in the stratum corneum and transitional layer of the epidermis. At the same time, alcian blue and PAS-positive GCs filled the lumen of the mucous gland. The affinity for PNA in the transitional layer, UEA-1 in stratum germinativum, and SBA in the mucous glands increased significantly during the same periods. In addition, new GCs, which are specific for SBA in the stratum corneum, BSL-1, RCA-1, sWGA, and LCA in some cells of the transitional layer, were detected.

CONCLUSIONS

Elevated GCs and a diversity of lectin affinities may be a result of seasonal adaptations related to hibernation. An affinity for PNA, UEA-1, and SBA in the frog skin may be useful as a marker of seasonal changes.

Transforming growth factor beta 1 expression in gastric carcinoma

Many types of human malignant tumor have been reported to amplify transforming growth factor-beta 1 (TGF-beta 1) gene and overexpress its protein. However, little work has been done about the content of TGF-beta 1 protein in tissue and blood of patients with malignant tumors. TGF-beta 1 protein of tissue (n = 29) and serum TGF-beta 1 levels in patients with gastric carcinoma (n = 62) were compared with those in normal subjects (n = 10) using a TGF-beta 1 enzyme-linked immunosorbent assay. Also, expression of TGF-beta 1 mRNA (n = 20) and immunohistochemical distribution of the protein (n = 70) in gastric carcinoma tissues were studied. The immunohistochemical expression of TGF-beta 1 protein was significantly correlated with the tissue TGF-beta 1 content (r = 0.45 : p < 0.05). The content of TGF-beta 1 was 311 +/- 212 ng/g wet carcinoma tissue. TGF-beta 1 mRNA was expressed in gastric carcinoma cells. However, unexpectedly serum TGF-beta 1 levels in patients with gastric carcinoma were lower (97.1 +/- 29.4 ng/ml) than those in normal subjects (140.3 +/- 85.7 ng/ml, P < 0.05). Our results support that the tumor cells directly produce TGF-beta 1 and that semiquantitative immunohistochemical staining method for TGF-beta 1 protein is a validative method for TGF-beta 1 protein quantitation.

Cytotoxic acylated Spermidine from a soft coral, Sinularia sp

A cytotoxic acylated spermidine was isolated from a Pacific soft coral, Sinularia sp. and its structure determined by NMR and mass spectral analysis. The acyl portion corresponds to (3E)-5-methyltetradec-3-enoic acid.

New antihepatotoxic cerebroside from Lycium chinense fruits

Two cerebrosides isolated from Lycium chinense fruits have been characterized as 1-O-beta-D-glucopyranosyl-(2S, 3R,4E,8Z)-2-N-palmitoyloctadecasphinga-4,8-dienine+ ++ (1) and 1-O-beta-D-glucopyranosyl -(2S,3R,4E,8Z)-2-N-(2'-hydroxypalmitoyl)octadecasph inga-4,8-dienine (2). While 2 is already known, the structure of 1 was determined by spectral and chemical studies. Incubation of CCl4-intoxicated hepatocytes with 1 and 2, respectively, significantly reduced the levels of glutamic pyruvic transaminase (GPT) and sorbitol dehydrogenase (SDH) released by injured cells.

Identification of castasterone, 6-deoxocastasterone, typhasterol and 6-deoxotyphasterol from the shoots of Arabidopsis thaliana

Endogenous brassinosteroids in the shoots of Arabidopsis thaliana were investigated. Castasterone, 6-deoxocastasterone, typhasterol and 6-deoxotyphasterol were identified by GC-MS. The co-occurrence of 6-deoxo-brassinosteroids and 6-oxo-brassinosteroids suggests that there are both early and late C6-oxidation pathways of brassinosteroids in A. thaliana.

Role of conserved Asn-Tyr-Asp-Tyr sequence in bacterial copper/2,4, 5-trihydroxyphenylalanyl quinone-containing histamine oxidase

Copper amine oxidase contains a covalently bound quinonoid cofactor, 2,4,5-trihydroxyphenylalanyl quinone (TPQ), which is synthesized by post-translational modification of a specific tyrosyl residue occurring in the highly conserved sequence, Asn-Tyr-(Asp/Glu)-Tyr. To elucidate the role(s) of the conserved sequence in the biogenesis of TPQ, each of the corresponding residues at positions 401-404 in the recombinant histamine oxidase from Arthrobacter globiformis has been replaced with other amino acids by site-directed mutagenesis. When Asn-401 was changed to Asp or Gln, the rate of TPQ formation by copper-dependent self-processing was 10(3)- to 10(4)-fold slower than in the wild-type enzyme. When Tyr-402 was replaced by Phe, TPQ was not formed at all, showing that Tyr-402 is essential as the precursor to TPQ. In contrast, Asp-403 could be replaced by Glu without changes in the rate of TPQ formation, whereas its replacement by Asn led to a marked decrease. Furthermore, when Tyr-404 was changed to Phe, TPQ was formed swiftly on incubation with copper ions, but the TPQ enzyme exhibited very low activity with altered substrate specificity. These results collectively indicate that a very rigorous structural motif is required for efficient formation of TPQ and for the catalytic activity in the active site of copper amine oxidases.

Recurrent acute pancreatitis: an additional manifestation of the "wandering spleen" syndrome"

A case of "wandering spleen" associated with recurrent pancreatitis and diagnosed with computed tomography (CT), is reported. The entity was also associated with a rotated, distended stomach, gastric outlet obstruction secondary to extrinsic compression of the duodenum, and partial small bowel obstruction secondary to extrinsic compression of a mobile, distended cecum that lay under the right diaphragm.

The action of the cholecystokinin-A receptor antagonist, devazepide, on the digestive system of the chicken

The influence of the cholecystokinin (CCK)-A receptor antagonist, devazepide (DVZ), on the chicken digestive tract was investigated. The passage of food from the crops of birds treated with DVZ was not significantly different from that of the control. DVZ treatment did not inhibit the biliary flow stimulated by the CCK analogue, caerulein. Dispersed chicken pancreatic acini stimulated with CCK were treated with various concentrations of DVZ. At 10-5 M, DVZ completely inhibited amylase release; this concentration was much higher than those reported to have similar effects in mammals. The results suggest that the action DVZ as a CCK antagonist in the chicken is very weak.

Biosynthesis of topa quinone cofactor in bacterial amine oxidases. Solvent origin of C-2 oxygen determined by Raman spectroscopy

Resonance Raman spectroscopy is an excellent technique for providing structural information on the 2,4, 5-trihydroxyphenylalanine quinone (TPQ) cofactor in copper-containing amine oxidases. This technique has been used to investigate the copper- and O2-dependent biosynthesis of the TPQ cofactor in phenylethylamine oxidase (PEAO) and histamine oxidase from Arthrobacter globiformis. Incubation of the holoenzyme in H218O causes frequency shifts at 1684(-26) cm-1 in PEAO and at 1679(-28) cm-1 in histamine oxidase, allowing this feature to be assigned to the C=O stretch of a single carbonyl group at the C-5 position. When apoprotein is reacted with Cu(II) and O2 in the presence of H218O, the resultant holoproteins show increased shifts of -3 to -6 cm-1 in a number of other vibrational modes, particularly at 411 and 1397 cm-1. Because these small shifts persist when the H218O-regenerated protein is back-exchanged into H216O, they can be assigned to oxygen isotope substitution at the C-2 postion. No isotope shifts are observed when apoprotein is regenerated with Cu(II) in the presence of 18O2. Thus, it is concluded that the C-2 oxygen atom of TPQ originates from H2O rather than O2. The isotope dependence of the 1397-cm-1 mode allows it to be assigned to the C O moiety at the C-2 position, with its low frequency being indicative of only partial double bond character. Similar frequency shifts due to 18O at C-2 are observed in the resonance Raman spectra of H218O-regenerated PEAO after derivatization of the C-5 carbonyl with either p-nitrophenylhydrazine (-5 cm-1 at 480 cm-1) or methylamine (-5 cm-1 at 1301 cm-1). Taken together, these results indicate that the TPQ cofactor in the native enzyme has substantial electron delocalization between the C-2 and C-4 oxygens and that only the C-5 oxygen has predominantly C=O character.

The interaction of clonidine and nitric oxide on feeding behavior in the chicken

Central administration of alpha 2-receptor agonists stimulate food intake in mammalian and avian species. Recently we reported that inhibition of nitric oxide (NO) synthase (NOS) decreased food intake in chickens. In the present study, we investigated whether the increased eating induced by clonidine (Clon), an alpha 2-receptor agonist, is attenuated by NOS inhibition. In the first experiment, four levels (0, 9.4, 18.8 or 37.5 nmol/10 microliters) of Clon were administered into the right lateral ventricle of chickens, and food intake was monitored. Clon increased 30 min-food intake in a dose-dependent manner. In a co-administration study of L-NG-nitro-arginine methyl ester HCl (LNNA), a NOS inhibitor, and Clon, LNNA (0, 1.5, 3.0 or 5.9 mumol) attenuated food intake induced by Clon (37.5 nmol) in a dose-dependent manner. Our results suggest the possibility that NO interacts with adrenergic neurons in the central nervous system to modulate feeding behavior in the chicken.

In vitro deveropment of porcine oocytes fertilized in vitro with spermatozoa preincubated in two different media

This study was conducted to clarify the effects of sperm concentration and media during preincubation on fertilization and development of porcine oocytes fertilized in vitro (IVF). The effect of porcine oviduct epithelial cell aggregates (POECA) on in vitro development of IVF embryos was also examined. Oocytes matured in vitro for 48 to 50 h were inseminated with epididymal spermatozoa preincubated at 2 sperm concentrations (1 - 2 x 10(8)/ ml vs 4 - 5 x 10(8)/ ml) for 3 h in either Dulbecco's phosphate buffered saline (PBS) or Brackett and Oliphant medium (BO). For capacitation, spermatozoa were treated with heparin (100microg / ml) for 15 min at 38.5 degrees C under 5% CO(2) in air. Cleavage and development to the blastocyst stage were evaluated on Day 3 and Day 8 after culture with or without POECA. The effect of sperm concentration on preincubation did not affect the fertilization rate, but preincubation in PBS medium did result in a higher fertilization rate (P < 0.05) than did the BO medium. The proportion of embryos undergoing cleavage and development to the blastocyst stage was significantly higher (P < 0.05) in the POECA co-culture group than in the group without POECA co-culture. The present results indicate that PBS medium can be utilized as a simple preincubation medium for porcine spermatozoa and that the presence of POECA during in vitro culture improved the development of IVF oocytes to the blastocyst stage.

Copper/topa quinone-containing histamine oxidase from Arthrobacter globiformis. Molecular cloning and sequencing, overproduction of precursor enzyme, and generation of topa quinone cofactor

The gene coding for histamine oxidase has been cloned and sequenced from a Coryneform bacterium Arthrobacter globiformis. The deduced amino acid sequence consists of 684 residues with a calculated molecular mass of 75,109 daltons and shows a high overall identity (58%) with that of phenethylamine oxidase derived from the same bacterial strain. Although the sequence similarities are rather low when compared with copper amine oxidases from other organisms, the consensus Asn-Tyr-Asp/Glu sequence, in which the middle Tyr is the precursor to the quinone cofactor (the quinone of 2,4,5-trihydroxyphenylalanine, topa) covalently bound to this class of enzymes, is also conserved in the histamine oxidase sequence. To identify the quinone cofactor, an overexpression plasmid has been constructed for the recombinant histamine oxidase. The inactive enzyme purified from the transformed Escherichia coli cells grown in a copper-depleted medium gained maximal activity upon stoichiometric binding of cupric ions. Concomitantly with the enzyme activation by copper, a brownish pink compound was generated in the enzyme, which was identified as the quinone of topa by absorption and resonance Raman spectroscopies of the p-nitrophenylhydrazine-derivatized enzyme and found at the position corresponding to the precursor Tyr (Tyr-402). Therefore, the copper-dependent autoxidation of a specific tyrosyl residue operates on the formation of the topa quinone cofactor in this enzyme, as recently demonstrated with the precursor form of phenethylamine oxidase (Matsuzaki, R., Fukui, T., Sato, H., Ozaki, Y., and Tanizawa, K. (1994) FEBS Lett. 351, 360-364).

Effect of glucose in the culture medium on development of horse oocytes matured and microfertilized in vitro

The development of in-vitro matured and microfertilized horse oocytes was examined in vitro. Fertilized oocytes were produced by 20-h insemination of in-vitro matured and partially zona-removed oocytes with frozen spermatozoa that had been treated with caffeine/calcium ionophore A23187 (fertilization rate 34.2%, monospermy rate 76.9%). Embryonic development was assessed by the number of nuclei stained with Giemsa solution. In Experiment 1, a continuous 8-day culture of the microfertilized oocytes in TCM199 or modified synthetic oviduct fluid (m-SOF) supplemented with 10% fetal bovine serum or 0.1% polyvinyl alcohol (PVA) in 5% O2, 5% CO2 and 90% N2 resulted in very few embryos developing beyond the 8-cell stage. In Experiment 2, the effects of different glucose concentrations (0, 0.5, 5.5 mM) in m-SOF/PVA during Days 1-4 and Days 5-8 of culture were examined. Proportions of oocytes having more than one nucleus ranged from 17.7% to 44.7% among the combinations of glucose concentrations. Supplementation with glucose at 0.5 mM during Days 1-4 followed by 5.5 mM during Days 5-8 resulted in the best embryo development; 12/55 (21.8%) nuclei-positive oocytes developed to the 8-16-cell stage, 11 (20.0%) developed to the 17-50-cell stage, and 5 (9.1%) comprised more than 50 cells and were assumed to be at the morula stage.

Combination chemotherapy with cyclophosphamide, vincristine, cisplatin and etoposide (COPE) combined with radiotherapy for small cell lung cancer

OBJECTIVES

Small cell lung cancer is sensitive to chemotherapy and radiotherapy. Nevertheless, responses are still short-lived and apparent cure remains for only limited disease patients.

METHODS

We combined cyclophosphamide (750 mg/m2 by intravenous infusion at first day) vincristine (2 mg intravenously at third day), cisplatin (20 mg/m2 intravenously for 3 days), and etoposide (100 mg/m2 intravenously for 3 days) with radiotherapy (total 300cGy over 4 weeks in 17 fractions) and treated 39 patients with small cell lung cancer who had received no prior systemic chemotherapy and radiotherapy.

RESULTS

1) Thirty-nine patients (limited disease: 17 patients, extensive disease 22 patients) were treated and 35 patients were evaluable for response. Overall response rate was 82.8% (complete response 28.6%, partial response 54.2%). 2) The median survival was 52 weeks for all patients and 58 weeks for limited disease and 45 weeks for extensive disease. There was no statically significant survival difference between the two patient groups. The median relapse-free survival time was 48 weeks. 3) Overall, treatment was well tolerated, with granulocytopenia being the most frequent toxicity.

CONCLUSIONS

Combination chemotherapy with COPE regimen combined with radiation therapy was effective as a first line therapy for SCLC.

Cholecystokinin is not a major regulator in the digestive system in the chicken

To find out whether physiological concentrations of cholecystokinin (CCK), a gastrointestinal hormone in mammals, are also active in chickens, the pancreatic amylase secretory response to CCK-8 was investigated in vitro. Rat pancreatic acini responded to the physiological concentration of CCK-8, but in chickens amylase release was induced at a concentration of CCK-8 1000 times higher than that observed in rats. In another experiment, biliary flow was tested with several doses of CCK-8. The bile flow was stimulated in a dose-dependent fashion, but a significant enhancement was not obtained at a concentration of 0.5 micrograms CCK-8/kg body weight, which was considerably higher than physiological ones. It is concluded that endogenous CCK does not have an important role in the digestive system in the chicken.

MR imaging of Ebstein's anomaly of the tricuspid valve

Ebstein's anomaly is an uncommon congenital developmental abnormality of the tricuspid valve that has a wide spectrum of pathologic anatomy. With the evolution of various surgical techniques, through assessment of the morphologic features and type of Ebstein's anomaly assumes greater practical importance. Although the diagnosis of Ebstein's anomaly is usually straightforward and is based on echocardiographic findings, there are limitations in defining pathologic anatomy in some cases. The purpose of this essay is to illustrate the MR findings in various types of Ebstein's anomaly.

Nitric oxide controls feeding behavior in the chicken

To investigate the effect of nitric oxide (NO) on food intake in the chicken, L-NG-nitro-arginine methyl ester HCl (L-NNA), an inhibitor of NO synthase, was applied. When i.p. administered, L-NNA significantly inhibited the food intake of broiler chickens in a dose response manner. Food ingestion was also depressed by the i.c.v. injection of L-NNA in a dose response fashion. The effect of L-NNA was attenuated by i.c.v. administration of L-arginine. These results suggest that central NO may control feeding behavior in the chicken.

Endogenous cholecystokinin is not a major regulator of food intake in the chicken

This study investigated whether or not endogenous cholecystokinin exerts satiety effects in chickens. After several doses (0, 1, 2 and 4 micrograms.kg body weight-1) of intravenous injection of caerulein, the bile flow was increased in a dose-dependent fashion. However, the pharmacological level of caerulein failed to suppress the food intake of chickens. Two potent stimulators of endogenous cholecystokinin, i.e., soybean trypsin inhibitor and phenylalanine were administered to chickens before feeding and food intake was determined over 2 h. The soybean trypsin inhibitor and phenylalanine did not alter food intake. Devazepide, a cholecystokinin-A receptor antagonist, significantly decreased amylase release from the dispersed chicken pancreatic acini stimulated by caerulein. However, devazepide did not improve food intake of the chicken. The results obtained suggest that endogenous cholecystokinin may not act as a satiety signal in chickens.