Expression of the intermediate filament vimentin in proliferating duct cells as a marker of pancreatic precursor cells

OBJECTIVES

The expression of the intermediate filament (IF) vimentin, usually considered a marker of mesenchymal cells, has been observed in the epithelial cells during embryogenesis, carcinogenesis, and dedifferentiation, suggesting that it might be useful as a marker of proliferating precursor cells in the pancreas.

METHODS

Rat pancreata at E18 and at different time points after partial pancreatectomy (Px) and human and neonatal pig pancreatic tissue sections and monolayer cultured pancreatic duct cells were observed. All tissues were simultaneously immunostained with pancytokeratin and vimentin antibodies. In costained duct cells, PDX-1 or PCNA expression was also analyzed using confocal microscope images.

RESULTS

In the rat embryonic pancreas at E18, all epithelial cells that formed ductlike structures expressed both cytokeratin and vimentin IF, whereas no duct cells costained for IF in the adult rat or neonatal pig pancreas. Such costaining reappeared in the following order: common pancreatic duct, main ducts, foci of regeneration and then disappeared completely at 30 days after Px. In humans, costaining was found in only 1 diabetic patient's pancreatic section, which was accompanied by massive duct cell proliferation. In monolayer culture, most of the duct cells of human and neonatal pigs coexpressed both IF proteins. Only a few costained duct cells also expressed PDX-1, and most of those cells were also stained with PCNA in rat embryonic pancreas and regenerating foci after partial Px.

CONCLUSIONS

Vimentin IF expression might be a useful marker for pancreatic precursor cells and could be used to investigate the concept of the dedifferentiation of fully matured duct cells during the process of the beta-cell neogenesis.

Rhodococcus equi pneumonia in a heart transplant recipient in Korea, with emphasis on microbial diagnosis

Rhodococcus equi is an opportunistic pathogen that usually causes infection in immunocompromised hosts. A heart transplant recipient who had been treated with amphotericin B for pulmonary aspergillosis showed newly developed multiple nodules with a central necrotic area in the right lower lobes. Cultures of several blood samples and an aspirate of the lung nodule yielded a Gram-positive coccobacillary bacterium, which was initially reported as a Corynebacterium species, but was later identified as R. equi by API CORYNE (bioMerieux SA, Marcy l'Etoile, France) and by demonstrating the production of 'equi factor'. The identification was subsequently confirmed by an R. equi-specific polymerase chain reaction (PCR). The patient was successfully treated with ciprofloxacin and azithromycin for 14 weeks. This is the first documented case of R. equi infection in Korea. There is a possibility of underestimation of R. equi infections due to the misidentification of the organism as a contaminating diphtheroid. Because R. equi will not respond to the conventional empirical therapy, the microbiology laboratory should identify R. equi in a timely manner. R. equi-specific PCR will be a useful confirmatory test in human infection.

A case of biphenotypic blast crisis of unclassified myeloproliferative disorder

We report a first case of biphenotypic blast crisis of unclassified myeloproliferative disorder (MPD). A 20-year-old patient presented with fever, splenomegaly, marked leukocytosis (603 x 10(3)/ micro l), and blasts in the peripheral blood. Since Ph chromosome and bcr-abl gene rearrangement were absent, the diagnosis of an unclassified MPD in the blast crisis phase was established. Immunophenotyping confirmed a biphenotypic crisis of myeloid and T-lymphoid antigens. The patient went into a complete remission after chemotherapy, but marked granulocytic hyperplasia (M:E ratio of 5.7) and 90% cellularity remained. Blast crisis recurred during subsequent intensification chemotherapy and the patient did not go into a complete remission regardless of the intense chemotherapy. The blast crisis transformed from unclassified MPD had a grave prognosis as it responded poorly to chemotherapy. This unique blast crisis is distinguishable from the blast crisis of chronic myelogenous leukemia.

Juniper oil inhibits the heat shock-induced apoptosis via preventing the caspase-3 activation in human astrocytes CCF-STTG1 cells

BACKGROUND

Brain astrocytes play a pivotal role in neuronal activities.

METHODS

An investigation was undertaken to determine whether juniper oil inhibits heat shock-induced apoptosis of astrocytes.

RESULTS

Juniper oil inhibited the heat shock-induced apoptosis in human astrocyte CCF-STTG1 cells. Pretreatment of the cells with juniper oil inhibited the heat shock-induced DNA fragmentation and condensation of nuclear chromatin. Juniper oil alone did not affect the apoptosis. Juniper oil inhibited the heat shock-induced caspase-3 activation and poly-ADP-ribose polymerase (PARP) fragmentation in the human astrocytes.

CONCLUSIONS

Juniper oil may inhibit the apoptosis of astrocytes by preventing the caspase-3 activation.

A hearing preservation technique for the resection of extensive jugular foramen tumors

OBJECTIVE

To describe a modified surgical approach for patients who maintain hearing function with jugular foramen tumors that extend to the posterior cranial fossa and the neck.

STUDY DESIGN

A retrospective review of 6 patients with jugular foramen tumors that were resected by a combined suboccipital and infralabyrinthine-transcervicomastoid approach.

METHODS

A combined suboccipital and infralabyrinthine-transcervicomastoid approach is characterized as follows: 1) There is no ablation of ear structures except the infralabyrinthine mastoid bone; the auricle is retracted anteriorly while preserving the bony wall and skin of the ear canal. 2) After superficial parotidectomy, a limited length of nerve VII from the intratemporal vertical segment is rerouted to divisions of the parotid portion. 3) The tumor is removed along with the internal jugular vein and sigmoid sinus, then the extended intracranial mass is resected through an additional suboccipital approach.

RESULTS

Five of the 6 patients had complete removal of all gross tumors. There were no major complications or mortalities. The preoperative levels of hearing were preserved in 5 of the 6 patients. Favorable facial function in the immediate postoperative period was noted in 4 of the 6 patients. Incomplete paralysis of 2 patients recovered eventually.

CONCLUSION

We propose that a combined suboccipital and infralabyrinthine-transcervicomastoid approach to the jugular foramen can provide sufficient exposure to resect most dumbbell-shaped tumors, and it could be the initial treatment of choice for patients with remnant hearing.

Tracheal compression by elongated aortic arch in patients with congenitally corrected transposition of the great arteries

We investigate the tracheal compression by aortic arch in patients with congenitally corrected transposition of the great arteries. Fourteen patients whose ascending aorta was connected to descending aorta on the contralateral side were divided into two groups according to the severity of tracheal compression on lateral angiogram: group 1 (stenosis > or = 50%, eight patients) and group 2 (stenosis < 50%, six patients). We compared the following variables between the groups: aortic size, lateral displacement of ascending aorta, retrosternal space, and contour of aortic arch. Spiral computed tomography (CT) was done in five patients of group 1. The ratio between measured and normal diameters of ascending aorta of group 1 was significantly larger than that of group 2 (1.57 +/- 0.14 compared to 1.19 +/- 0.26, p = 0.014). There was linear correlation between the tracheal compression and aortic size (r = 0.69, p = 0.001). The ascending aorta was positioned more laterally and the aortic arch was located more posteriorly in group 1. In four patients with decreased tracheal compression after surgery, aortic size decreased and the ascending aorta restored its anterior position. Spiral CT showed transversely oriented aortic arch and severe tracheal compression in the anteroposterior direction by aortic arch. The tracheal compression by aortic arch in corrected transposition is common when the descending aorta is located on the contralateral side of the ascending aorta. Aortic size, posterior position, elongation, and end-on appearance of the aortic arch are the useful predictors of tracheal compression.

The activation of PI 3-K and PKC zeta in PMA-induced differentiation of HL-60 cells

The human myelocytic leukemia cell line HL-60 is a useful model for the study of cellular differentiation. Phorbol 12-myristate 13-acetate (PMA) induces the monocyte/macrophage-like differentiation of HL-60 cells and results in growth arrest, increasing adherence. In PMA-induced differentiation of HL-60 cells, phosphoinositide 3-kinase (PI 3-K) activity was measured as phosphatidylinositol3P recovery from phosphatidylinositol by in vitro kinase assay. PI 3-K activity was increased in HL-60 cells that were stimulated by 20 nM PMA and the activity was inhibited by pretreatment with 20 microM LY294002, a specific inhibitor of PI 3-K. Members of the protein kinase C (PKC) family have been suggested to be one of the downstream targets of PI 3-K. PKC zeta is one of the atypical PKCs, non-diacylglycerol-responsive PKCs, and the activity was measured by the ability of phosphorylation onto myelin basic protein. PMA also induced the activation of PKC zeta during monocytic differentiation of HL-60 cells, and LY294002-pretreated cells failed to induce PKC zeta activation. The activity of PI 3-K is essential for PKC zeta activation, and LY294002 blocks both monocytic differentiation of HL-60 cells and activation of PKC zeta during PMA-induced cell differentiation. This implies that activated PI 3-K subsequently stimulates the PKC zeta in the process of PMA-induced monocytic differentiation.

Normal pericardial fluid in the fetus: color and spectral Doppler analysis

OBJECTIVES

To estimate the incidence of sonographic identification of pericardial fluid in normal fetuses and to evaluate the flow pattern of pericardial fluid by using color and spectral Doppler techniques.

METHODS

We evaluated 27 normal fetuses for the presence of pericardial fluid by using gray-scale two-dimensional and M-mode ultrasound, and color and spectral Doppler techniques.

RESULTS

Pericardial fluid was detected in 52% of cases by two-dimensional and M-mode ultrasound and in 81% of cases by color Doppler. The pericardial fluid moved towards the ventricles during systole and towards the atria during diastole. In 9 of 22 fetuses with pericardial fluid identified by color Doppler, spectral waveforms were obtained. The waveforms confirmed the bidirectional flow pattern identified at color Doppler. In six cases there was monophasic systolic and biphasic diastolic flow. In the remaining three cases, the flow was monophasic during both systole and diastole.

CONCLUSIONS

Pericardial fluid can be identified with color Doppler in the majority of normal fetuses. It characteristically shows bidirectional flow as it moves with ventricular systole and diastole. Spectral waveforms can be obtained from the pericardial fluid. The presence of pericardial fluid per se should not be considered as abnormal. Color-coded pericardial fluid should not be mistaken for coronary artery blood flow.

Aneurysm of the membranous septum in critical pulmonary stenosis: spontaneous rupture after balloon dilatation

We report a case of critical pulmonary valve stenosis in which congenital aneurysm of the membranous septum ruptured spontaneously after balloon dilatation of the pulmonary valve. It is considered that the chronic mechanical trauma with phasic protrusion and collapse of the aneurysm during the cardiac cycles was responsible for an aneurysm rupture.

The effect of cilostazol on glucose tolerance and insulin resistance in a rat model of non-insulin dependent diabetes mellitus

BACKGROUND

It has been reported that many peripheral vasodilating drugs might improve insulin resistance. Cilostazol, a antithrombotic agent, increases peripheral blood flow in non-insulin dependent diabetic patients. The effect of cilostazol treatment on insulin resistance in streptozotocin (STZ)-induced non-insulin dependent diabetic Wistar rats was examined.

METHODS

About a half of two-day old neonate siblings were injected intraperitoneally with STZ and maintained for six months, at which time they were compared with age-matched control rats for intraperitoneal glucose tolerance test (IPGTT) and for glucose infusion rate (GINF) in a euglycemic hyperinsulinemic glucose-clamp study. After that, these studies were also performed after feeding rat chow containing cilostazol (100 mg/kg/day) to rats with STZ-induced non-insulin dependent diabetes mellitus for four-weeks and compared with those of age-matched control rats.

RESULTS

In the intraperitoneal glucose tolerance test studies, plasma glucose levels of STZ-induced non-insulin dependent diabetic rats were significantly higher and plasma insulin levels significantly lower than those of age-matched control rats in the age of six months. Glucose infusion rate was lower in STZ-induced non-insulin dependent diabetic rats than those of age-matched control rats. However, after a four-week cilostazol treatment, glucose infusion rate of STZ-induced non-insulin dependent diabetic rats was not significantly different from that of control rats.

CONCLUSION

These findings suggested that cilostazol may improve insulin resistance in STZ-induced non-insulin dependent diabetic rats.

Structure-activity relationships of apio nucleosides as potential antiviral agents

Several types of novel apio nucleosides were synthesized starting from 1,3-dihydroxyacetone and evaluated for antiviral activity. Among compounds tested, amino substituted apio dideoxynucleosides exhibited anti-HBV activity, while thioapio dideoxynucleosides were found to be active against HIV-1. Apio dideoxydidehydro nucleosides showed moderate to potent anti-HCMV activity, but their bioisosteric thioapio dideoxydidehydro nucleosides did not exhibit any significant antiviral activity.

Synthesis and antiviral activity of D- and L-2'-azido-2',3'-dideoxy-4'-thiopyrimidine and purine nucleosides

Novel D- and L-2'-azido-2',3'-dideoxy-4'-thionucleosides were synthesized starting from L- and D-xylose via D- and L-4-thioarabitol derivative as key intermediates and evaluated for antiviral activity, respectively. When the final nucleosides were tested against HIV-1, HSV-1, HSV-2, and HCMV, they were found to be only active against HCMV without cytotoxicity up to 100 micrograms/ml.

Development of multianalyte sensor arrays composed of chemically derivatized polymeric microspheres localized in micromachined cavities

The development of a chip-based sensor array composed of individually addressable polystyrene-poly(ethylene glycol) and agarose microspheres has been demonstrated. The microspheres are selectively arranged in micromachined cavities localized on silicon wafers. These cavities are created with an anisotropic etch and serve as miniaturized reaction vessels and analysis chambers. A single drop of fluid provides sufficient analysis media to complete approximately 100 assays in these microetch pits. The cavities possess pyramidal pit shapes with trans-wafer openings that allows for both fluid flow through the microreactors/analysis chambers and optical access to the chemically sensitive microspheres. Identification and quantitation of analytes occurs via colorimetric and fluorescence changes to receptor and indicator molecules that are covalently attached to termination sites on the polymeric microspheres. Spectral data are extracted from the array efficiently using a charge-coupled device allowing for the near-real-time digital analysis of complex fluids. The power and utility of this new microbead array detection methodology is demonstrated here for the analysis of complex fluids containing a variety of important classes of analytes including acids, bases, metal cations, metabolic cofactors, and antibody reagents.

Beta-cell differentiation from a human pancreatic cell line in vitro and in vivo

Cell transplantation therapy for diabetes is limited by an inadequate supply of cells exhibiting glucose-responsive insulin secretion. To generate an unlimited supply of human beta-cells, inducibly transformed pancreatic beta-cell lines have been created by expression of dominant oncogenes. The cell lines grow indefinitely but lose differentiated function. Induction of beta-cell differentiation was achieved by stimulating the signaling pathways downstream of the transcription factor PDX-1, cell-cell contact, and the glucagon-like peptide (GLP-1) receptor. Synergistic activation of those pathways resulted in differentiation into functional beta-cells exhibiting glucose-responsive insulin secretion in vitro. Both oncogene-expressing and oncogene-deleted cells were transplanted into nude mice and found to exhibit glucose-responsive insulin secretion in vivo. The ability to grow unlimited quantities of human beta-cells is a major step toward developing a cell transplantation therapy for diabetes.

Bilateral congenital diaphragmatic hernia: diagnostic clues at fetal sonography

Bilateral congenital diaphragmatic hernia is a rare, life-threatening malformation. We describe a case of bilateral Bochdalek hernia diagnosed prenatally. The sonographic clues to the diagnosis were anterior displacement of the heart with relatively minimal lateral shift. The definitive diagnosis was made by demonstrating the liver in the right thorax and bowel loop and stomach in the left thorax. Color and power Doppler demonstrated the hepatic vessels embracing both sides of the heart from behind.

Syntheses and structure--activity relationships of novel apio and thioapio dideoxydidehydronucleosides as anti-HCMV agents

On the basis of the fact that apio dideoxynucleosides, in which the furanose oxygen and the C2 of the 2,3-dideoxyribose are transposed, exhibited potent anti-HIV activity and 2',3'-dideoxy-2',3'-didehydronucleosides also showed potent anti-HIV activity, we synthesized apio dideoxydidehydronucleosides in which the oxygen atom and the double bond of the 2,3-dideoxy-2,3-didehydroribose are exchanged. The thioapio dideoxydidehydronucleosides were also synthesized since sulfur serves as a bioisostere of oxygen. Apio dideoxydidehydronucleosides 13a--f were synthesized starting from 1,3-dihydroxyacetone, utilizing phenylselenenyl chemistry as a key step. The ratio of the anomeric mixture was variable from 1:1 to 5:1 during the condensation of nucleosidic bases with the phenylselenyl acetate 11 in the presence of a Lewis acid. This is in contrast with other glycosyl donors such as 5-O-(tert-butyldiphenylsilyl)-2-phenylselenenyl-2,3-dideoxyribosyl acetate which shows excellent neighboring group effect (alpha:beta = 1:99). Thioapio dideoxydidehydronucleosides 22a,b were synthesized from the lactone 9 via thiolactone 17 as a key intermediate which was synthesized from dicyclohexylcarbodiimide coupling of the mercapto acid produced from the basic hydrolysis of thioacetate 16. The majority of apio analogues synthesized in this study exhibited moderate to potent anti-HCMV activity, among which the 5-fluorouracil derivative 13c was found to be the most potent against HCMV, while thioapio analogues showed no activity against HCMV. However, all synthesized compounds did not exhibit any significant activities against HIV-1, HSV-1, and HSV-2. The fact that apio dideoxydidehydronucleosides were active against HCMV suggests that the apio dideoxydidehydro sugar moiety can serve as a novel template for the development of new antiviral agents.

Molecular cloning and characterization of alternatively spliced transcripts of the turkey pituitary adenylate cyclase-activating polypeptide

Pituitary adenylate cyclase-activating polypeptide (PACAP) increases the release of growth hormone (GH) and prolactin (PRL) in mammals. However, the evolutionary and functional relationships of PACAP, GH, and PRL are not clear. To understand how PACAP is regulated in the turkey, a turkey PACAP (tPACAP) cDNA has been cloned by the combination of reverse transcription-polymerase chain reaction and the rapid amplification of cDNA 5'- and 3'-ends. The deduced amino acid sequence of tPACAP-38 and turkey PACAP-related peptide (tPRP) displayed 87-97 and 52-63% similarity when compared to a variety of known PACAP-38 and PRP sequences, respectively. Two major transcripts (1.3 and 3.0 kb) of tPACAP were detected by Northern blot analysis. The highest levels of tPACAP mRNA were shown to be expressed in the hypothalamus, the cerebellum, and the cerebrum. In contrast, most of the other tissues tested expressed relatively low steady-state levels of tPACAP mRNA. Alternative splicing of tPACAP resulted in the expression of two different isoforms. The smaller form of tPACAP was expressed in the hypothalamus during early embryonic development and decreased significantly in later stages.

Changing trends in clinical manifestations of laryngeal tuberculosis

OBJECTIVES/HYPOTHESIS

Despite the dramatic decrease in the incidence of laryngeal tuberculosis, the disease has gained new interest as a result of claims that it has changed its clinical patterns. The aim of this study is to evaluate the changing trends in clinical manifestations of laryngeal tuberculosis.

STUDY DESIGN

Retrospective clinical analysis.

METHODS

Clinical analysis of 22 patients with pathologically confirmed laryngeal tuberculosis was carried out retrospectively.

RESULTS

Patients' ages ranged from 22 to 75 years. The male-to-female ratio was 2.14 to 1. The most frequent chief complaint was hoarseness. The true vocal cord and the false vocal cord were commonly involved, and 11 patients showed single lesions. Among 22 patients, only 7 had active pulmonary tuberculosis, and 9 were proven to have normal lung status. The patients with active pulmonary tuberculosis showed more ulcerative and multiple lesions. The patients with normal lung status showed nonspecific, polypoid, and single lesions. All patients responded satisfactorily to antituberculous medication.

CONCLUSIONS

The clinical manifestations of laryngeal tuberculosis have changed and seem to be different from those of classic reports. It can even occur without pulmonary tuberculosis, and the characteristics of lesions seem to be more nonspecific. It might be important to consider tuberculosis in the differential diagnosis of nonspecific laryngeal disease.

Twisted atrioventricular connections in double inlet right ventricle: evaluation by magnetic resonance imaging

Twisted atrioventricular connections occur almost exclusively in the hearts with biventricular atrioventricular connections. Only one example of double inlet left ventricle has been illustrated in which the axes of the two atrioventricular valves crossed each other. We describe herein three patients, and one autopsied specimen, with double inlet right ventricle in which magnetic resonance imaging clearly demonstrated twisted atrioventricular connections.

Angiographic findings of persistent primitive hepatic venous plexus with underdevelopment of the infrahepatic inferior vena cava in pediatric patients

OBJECTIVE

We describe the angiographic diagnosis and significance of persistence of the primitive hepatic venous plexus with underdevelopment of the infrahepatic inferior vena cava.

CONCLUSION

We recommend that inferior venacavography be performed in routine assessment before surgery of patients with azygos or hemiazygos continuation of the inferior vena cava, in whom redirection of systemic venous blood to the pulmonary artery is contemplated.

Fetal echocardiographic features of twisted atrioventricular connections

We present an example of corrected transposition with twisted discordant atrioventricular connections in which both fetal and postnatal echocardiograms were obtained. We correlate the fetal echocardiograms with the postnatal echocardiograms, placing emphasis on the echocardiographic clues to the diagnosis which were present in fetal life. The diagnosis should be suspected when the cardiac chambers and great arteries show an unexpected spatial relationship for the given segmental connections, and when the axes of opening of the atrioventricular valves are not parallel.

Fetal cardiac dextroposition in the absence of an intrathoracic mass: sign of significant right lung hypoplasia

We reviewed our experience of fetal cardiac dextroposition in the absence of an intrathoracic mass. Ten cases were found by fetal echocardiography to have a normal cardiac axis, but the heart was shifted into the right chest and the amount of right lung tissue was reduced. At birth seven of the infants had confirmed structural heart disease (70%), including three with scimitar syndrome. Two infants had additional extracardiac anomalies (20%). Seven infants born at term had clinical pulmonary hypertension with a diagnosis of right lung hypoplasia in all of them. Two neonates died owing to significant heart disease (one with scimitar syndrome and the other with hypoplastic left heart syndrome). Of the three pregnancies that were terminated, the two fetuses with autopsies had severe right lung hypoplasia. Fetal cardiac dextroposition and right pulmonary artery hypoplasia in the absence of an intrathoracic mass are important signs of right lung hypoplasia, which can be associated with significant pathologic cardiac and extracardiac conditions.

The Drosophila caspase DRONC cleaves following glutamate or aspartate and is regulated by DIAP1, HID, and GRIM

The caspase family of cysteine proteases plays important roles in bringing about apoptotic cell death. All caspases studied to date cleave substrates COOH-terminal to an aspartate. Here we show that the Drosophila caspase DRONC cleaves COOH-terminal to glutamate as well as aspartate. DRONC autoprocesses itself following a glutamate residue, but processes a second caspase, drICE, following an aspartate. DRONC prefers tetrapeptide substrates in which aliphatic amino acids are present at the P2 position, and the P1 residue can be either aspartate or glutamate. Expression of a dominant negative form of DRONC blocks cell death induced by the Drosophila cell death activators reaper, hid, and grim, and DRONC overexpression in flies promotes cell death. Furthermore, the Drosophila cell death inhibitor DIAP1 inhibits DRONC activity in yeast, and DIAP1's ability to inhibit DRONC-dependent yeast cell death is suppressed by HID and GRIM. These observations suggest that DRONC acts to promote cell death. However, DRONC activity is not suppressed by the caspase inhibitor and cell death suppressor baculovirus p35. We discuss possible models for DRONC function as a cell death inhibitor.