Bladder wall calcification after intravesical chemotherapy with mitomycin C--a case report

Bladder wall calcification has relatively few etiologies. We present such a case and review the literature to discuss it and the method for management. This case suffered from bladder wall calcification about 3 years after intravesical chemotherapy of mitomycin C. It was found accidentally during the transurethral resection of recurrent bladder tumor. The pathology confirmed the recurrence of transitional cell carcinoma combined with marked calcification. A repeat cystoscopy was done 3 months later. Massive calcified deposits in bladder wall especially in lesion of previous transurethral resection were still noted. Randomized biopsy showed dystrophic calcification without evidence of malignancy. We suggest that biopsy and/or resection (if possible) is a reasonable approach to eliminate the possibility of invasive bladder cancer.

Risk factors for mortality in primary isolated coronary artery bypass grafting surgery

BACKGROUND AND PURPOSE

Identifying the risk factors for mortality in coronary artery bypass grafting (CABG) surgery is important to improve surgical results. The purpose of this study was to identify the risk factors for mortality in primary isolated CABG in a series of Taiwanese patients.

METHODS

Medical records of 914 patients who underwent primary isolated CABG surgery in Veterans General Hospital-Taipei during the period from January 1, 1991, to December 31, 1995, were reviewed. Eighteen clinical and seven operative variables were included in the univariate and multivariate analyses to identify the determinants of mortality in CABG surgery.

RESULTS

Thirty-one patients (3.4%) died within 30 days after surgery; 41 (4.5%) died during hospitalization for the procedure. After univariate and multivariate analyses, emergency surgery, history of myocardial infarction, concomitant peripheral artery occlusive disease (PAOD), and prolonged cardiopulmonary bypass (CPB) were found to be significant determinants of mortality in primary isolated CABG. Other variables, including age, sex, angina class, NYHA class, diabetes mellitus, the number of anastomoses, aortic cross-clamp time, stenosis of the left main coronary artery, the number of stenotic coronary arteries, history of congestive heart failure, and a left ventricular ejection fraction less than 35%, were not significant determinants of mortality. Patients undergoing emergency surgery were found to be at highest risk of mortality.

CONCLUSIONS

Patients undergoing emergency surgery who had a history of myocardial infarction, concomitant PAOD, or prolonged CPB were at higher risk of mortality in CABG surgery. More comprehensive techniques in myocardial protection, surgical procedures, and postoperative care should be used in the treatment of high-risk patients to reduce mortality.

Glycophorin A dimerization and band 3 interaction during erythroid membrane biogenesis: in vivo studies in human glycophorin A transgenic mice

Band 3 and glycophorin A (GPA) are the 2 most abundant integral proteins in the human erythrocyte membrane. Earlier studies suggested that the 2 proteins may associate not only in the mature erythrocyte membrane, but also during their posttranslational processing and intracellular trafficking. The purpose of this study was to directly examine the GPA-band 3 interaction in vivo and determine the nature of this association during erythroid membrane biogenesis. Transgenic mice were generated expressing the human glycophorin A gene and were used to examine how the induction of human GPA expression affected the levels of murine GPA and band 3 expression in the red cell membrane. Murine GPA expression was reduced in erythrocytes expressing human GPA, whereas the level of band 3 expression remained constant, implying a tight coupling of band 3 and GPA expression in the membrane of mature red cells. In vivo GPA dimerization was not modulated solely by the GPA transmembrane motif, but the distance between this motif and the basic residues on the cytoplasmic side of the transmembrane domain may also be important. In addition, GPA monomers with varying degrees of glycosylation dimerized, providing clear evidence that carbohydrate structures on the extracellular domain do not affect dimerization. The association between the multiple transmembrane-spanning protein, band 3, and the single transmembrane-spanning sialoglycoprotein, GPA, may serve as a model for interactions of other multi-pass and single-pass polypeptides during membrane biogenesis.

The intrinsic stability of the noble gas-coordinated transition-metal complex ions

Density-functional-theory and high-level ab initio calculations have been performed on the [AuXe4]2+ ion and some other hypothetical xenon-, krypton-, and argon-coordinated transition-metal complex cations in the gas phase. Geometry optimization at the QCISD(T) level using a (6s7p4d2f1g) basis set for Au and a (4s4p2d1f) set for Xe predicted Au-Xe bond lengths in good agreement with the AuXe4(2+)(Sb2F11-)2 crystal structure. The ligand-binding energies of the [AuXe4]2+, [AuXe4]3+, and [PtXe4]2+ ions were predicted to be 229, 565, and 233 kcal/mol, respectively, at the CCSD(T) level. It is found that higher-level correlation effects are important to obtain accurate geometry parameters. The calculated results also indicated that various trivalent, tetravalent, and hexavalent transition-metal complexes of xenon or krypton might also be intrinsically stable.

The pressure waveform of coronary sinus in human hearts

BACKGROUND

The pressure waveform of coronary sinus in human hearts has never been well described. Retrograde cardioplegia perfusion has become a popular method of myocardial protection in recent years, and identification of the pressure waveform of the coronary sinus might help intubate the coronary sinus in retrograde cardioplegia perfusion by differentiating it from that of the right atrium. The purpose of this study is to identify the pressure waveform of the coronary sinus.

METHODS

We inserted a catheter into the coronary sinus under direct vision via a right atriotomy after completion of open heart operation in eight patients. The pressure waveforms of coronary sinus and central venous line, as well as the electrocardiogram (EKG), were recorded simultaneously after the patient was stable and weaned from the cardiopulmonary bypass. The recorded pressure waveforms of coronary sinus and central venous line were compared.

RESULTS

The pressure waveform of coronary sinus was found to have three peaks, more prominent than those of the central venous line waveform.

CONCLUSIONS

The pressure waveform of coronary sinus could be distinguished from that of the central venous line. The difference might help coronary sinus cannulation for retrograde cardioplegia perfusion.

Microarray profiling of gene expression patterns in bladder tumor cells treated with genistein

Microarray technology was used to gain an insight into the molecular events of tumor cell growth inhibition mediated by the soy isoflavone genistein. For this, a susceptible bladder tumor line TCCSUP was treated with the inhibitory dose (50 microM) of genistein for various periods of time, followed by mRNA isolations, cDNA probe preparations, and hybridization individually to cDNA chips containing 884 sequence-verified known human genes. After analyzing the hybridization signals with a simple quantitative method developed by this study, we detected that egr-1, whose expression has been associated with proliferation and differentiation, was transiently induced and this expression pattern was later confirmed by RT-PCR. Thus, microarray technology is a reliable and powerful tool for profiling gene expression patterns in many biological systems related to cancer. We further detected many groups of genes with distinct expression profiles and most of them encode for proteins that regulate the signal transduction or the cell cycle pathways. These genes warrant further investigation as regards their roles in the susceptibility of the tumor cell line to the antitumor drug.

Adrenal cyst--a case report

Adrenal cysts are rare and mostly silent clinically. Herein we report a case of adrenal cyst. A 55-year-old female was incidentally found to have a left suprarenal cystic lesion with a calcified wall by abdominal sonography during a work-up for her epigastralgia and left flank pain. Then, computed tomography (CT) revealed a left adrenal cystic mass with wall calcification, magnetic resonance imaging (MRI) showed left retroperitoneal cystic mass with fluid content, and angiography demonstrated an avascular lesion. Surgical exploration was performed via a flank incision and a calcified cystic adrenal mass was excised. The pathologic diagnosis was adrenal pseudocyst with calcified wall. We discuss the diagnosis and management of adrenal cyst and briefly review the literature.

Cystitis glandularis mimics bladder cancer--three case reports and literature review

Cystitis glandularis is an uncommon proliferative disorder of the mucus-producing glands within the mucosa and submucosa of urinary bladder epithelium. We report three cases with gross hematuria on first presentation. Both sonography and computer tomography revealing bladder tumor and transurethral resection was performed in all three cases. Cystitis glandularis was confirmed by pathology. Short-term follow-up of sonography and cystoscopy showed good results.

Corneal melt as the initial presentation of primary Sjögren's syndrome

Corneal melting is a rare complication of S ogren's syndrome (SS). Previously reported cases of corneal ulceration occurred in patients with established SS, usually secondary to RA. We describe the first case of corneal ulceration with stromal melting as the initial presentation of primary SS. A 79-year-old man without prior sicca symptoms developed a large sterile corneal ulcer that required extensive treatment over several months with ocular lubricants, systemic immunosuppressives, and surgical repair. Evaluation for an underlying connective tissue disease revealed positive antinuclear antibodies (1:640 speckled) and anti-SSA antibody. A lip biopsy established the diagnosis of SS. Ulceration later occurred in the contralateral eye. Two years after the last corneal ulcer and no longer taking prednisone, the patient's ocular disease remained quiescent taking azathioprine 175 mg and hydroxychloroquine 400 mg daily. This case highlights the potential for primary SS to present with serious ocular complications despite lack of a priori sicca symptoms, as well as the importance of immunosuppressive therapy in the treatment of this complication.

The influence of inserting a Fuji pressure sensitive film between the tibiofemoral joint of knee prosthesis on actual contact characteristics

OBJECTIVE

To investigate the influence of inserting a Fuji pressure sensitive film between the tibiofemoral joint of knee prosthesis on actual contact characteristics.

DESIGN

A finite element analysis was used to investigate the alteration of contact characteristics of the tibiofemoral joint due to inserting a pressure sensitive film between the contacting surfaces.

BACKGROUND

The discrepancy between actual contact behaviors of tibiofemoral joint of knee prosthesis and the measurement using Fuji pressure sensitive film was not discussed extensively. The change of direct contact circumstance of the tibiofemoral joint due to inserting a pressure sensitive film was not well reported.

METHOD

A two-dimensional finite element model of the tibiofemoral joint of knee prosthesis in the sagittal plane was constructed. Four different radii of the femoral component were used to investigate the conformity effect. Two-layers of plane strain element were used to model the pressure sensitive film. The influence of inserting a pressure sensitive film on the actual contact characteristics was analyzed by comparing the results of the change in contact radius.

RESULTS

Inserting a pressure sensitive film between contacting surfaces would disturb the original contact behaviors, especially in the lowest conformity design. The maximum difference of contact radius between the model simulating actual contact circumstance and the model with inserting a pressure sensitive film between contacting surface was 77% in the lowest conformity condition at the smallest load.

CONCLUSIONS

This study proposes a quantitative analysis of contact characteristics in the tibiofemoral joint of knee prosthesis between the models with and without inserting a pressure sensitive film into the contact surface. The measurement of contact area in artificial tibiofemoral joints by using Fuji pressure sensitive film is always overestimated its true contact area by 14-77%.

RELEVANCE

This study revealed the measurement of contact characteristics of artificial tibiofemoral joints by using Fuji pressure sensitive film which depends on not only the applied load, but also the conformity and material properties of the contact surface. Therefore, the information of the conformity and material properties of the contact surface should be provided as well as the applied load wherever a measurement of contact characteristics using Fuji pressure sensitive film is analyzed and interpreted.

Adult Wilms' tumor associated with polycythemia--a case report

Both Wilms' tumor (nephroblastoma) in adults and polycythemia in Wilms' tumor are rare. Herein we report an extremely rare case of adult Wilms' tumor associated with polycythemia. A 41-year-old female was incidentally found to have right renal mass by abdominal sonography in a routine health examination. Laboratory examination revealed polycythemia (hemoglobin 20.2 g/dL). Although physical examination was unremarkable, CT scan revealed an homogeneous mass at the middle pole of right kidney, and chest x-ray revealed no metastatic lesions. Right radical nephrectomy was performed smoothly. Grossly, the tumor of 5 x 4.5 x 4.5 cm in size was well circumscribed, and had no vascular structure or collecting system involvement. Microscopic features were consistent with adult nephroblastoma. The post-operative course was uneventful. At follow-up, the patient was well, showed no evidence of recurrence and her hemoglobin level had returned to normal (hemoglobin 14.5 g/dl). We suggest that the relationship between polycythemia and Wilms' tumor should be carefully evaluated before surgical treatment.

Rh type B glycoprotein is a new member of the Rh superfamily and a putative ammonia transporter in mammals

Ammonium transporters play a key functional role in nitrogen uptake and assimilation in microorganisms and plants; however, little is known about their structural counterpart in mammals. Here, we report the molecular cloning and biochemical characterization of Rh type B glycoproteins, human RhBG and mouse Rhbg, two new members of the Rh family with distinct tissue specificities. The RhBG orthologues possess a conserved 12-transmembrane topology and most resemble bacterial and archaeal ammonium transporters. Human RHBG resides at chromosome 1q21.3, which harbors candidate genes for medullary cystic kidney disease, whereas mouse Rhbg is syntenic on chromosome 3. Northern blot and in situ hybridization revealed that RHBG and Rhbg are predominantly expressed in liver, kidney, and skin, the specialized organs involving ammonia genesis, excretion, or secretion. Confocal microscopy showed that RhBG is located in the plasma membrane and in some intracellular granules. Western blots of membrane proteins from stable HEK293 cells and from mouse kidney and liver confirmed this distribution. N-Glycanase digestion showed that RhBG/Rhbg has a carbohydrate moiety probably attached at the NHS motif on exoloop 1. Phylogenetic clustering, tissue-specific expression, and plasma membrane location suggest that RhBG homologous proteins are the long sought major ammonium transporters in mammalians.

Analysis of estrogenic hormones in municipal wastewater effluent and surface water using enzyme-linked immunosorbent assay and gas chromatography/tandem mass spectrometry

Although the estrogenic hormones 17 beta-estradiol and 17 alpha-ethinyl estradiol can be quantified in polluted waters by gas chromatography/mass spectrometry (GC/MS) and gas chromatography/tandem mass spectrometry (GC/MS/MS), the compounds often are present at concentrations below detection limits. Enzyme-linked immunosorbent assays (ELISAs) provide a sensitive and robust means of quantifying estrogenic hormones in wastewater effluents and surface waters. Results from ELISA analysis of estrogenic hormones in secondary wastewater effluent indicate concentrations comparable to those that cause vitellogenesis in fish. Confirmatory analyses by GC/MS/MS are consistent with ELISA results. Effluent filtration, using sand filtration or microfiltration, removes approx. 70% of the hormones from secondary effluent, while advanced treatment, using reverse osmosis, removes more than 95% of hormones. The detection limits for estrogenic hormones are approx. 0.1 ng/L in wastewater effluent and 0.05 ng/L in surface water. The ELISA technique provides a relatively simple and practical method of assessing the fate of estrogenic hormones in engineered and natural systems.

Morphometric identification of luminal narrowing of myocardial capillaries after cardioplegic arrest

BACKGROUND

Because there is no smooth muscle cell surrounding the capillary endothelial cells, the effect of coronary microcirculation at the capillary level following cardioplegic arrest and reperfusion would be much different from that of resistant arterioles. We therefore studied the effect of hypothermic blood cardioplegic arrest and subsequent reperfusion on the myocardial capillaries in cardiac operation patients.

METHODS

Twenty-seven patients who underwent cardiac operations were included in this study. Three sequential biopsies (preischemia, ischemia, and reperfusion) were obtained from the right atrium. This study was restricted to blood vessels with a diameter of less than 8 microns. Ten randomly selected capillaries from each biopsy were measured for luminal surface area, endothelial cytoplasmic surface area, and total cross-sectional surface area of capillaries.

RESULTS

From stereologic morphometric studies, the serial changes in total cross-sectional surface area were not statistically significant (p = 0.152). However, there was a significant swelling of endothelial cytoplasm following ischemia and reperfusion (p = 0.0007). Meanwhile, changes in luminal surface area of capillaries following ischemia and reperfusion were also remarkable (p = 0.0008).

CONCLUSIONS

The most striking finding of this study was the progressive decrease in capillary lumen during ischemia and after reperfusion. The swelling of endothelial cells is a major determinant of luminal narrowing of capillaries in patients receiving cardioplegic arrest.

Molecular Mechanics and Calorimetric Studies of Phosphatidylethanols

Phosphatidylethanols (PEths) are negatively charged diacyl phospholipids that are ubiquitously present in humans under the condition of alcohol intoxication. These lipids, derived in vivo from other naturally occurring phospholipids such as phosphatidylcholines (PC) via transphosphatidylation reaction as catalyzed by phospholipase D in the presence of ethanol, are well known to affect many biochemical properties of the cell membranes in humans. In this communication, we applied the combined approach of molecular mechanics (MM) simulations and high-sensitivity differential scanning calorimetry (DSC) to investigate the structure and phase transition behavior of PEth. We first determined the energy-minimized structures of tetrameric C(15):C(15)PEth arranged in two types of packing motif by the MM approach. An inwardly bent orientation of the lipid headgroup was observed; specifically, the methyl terminus of PEth's headgroup was juxtaposed intramolecularly to the C(2) atom of the sn-2 acyl chain. Clearly, this headgroup conformation was rather unique among all naturally occurring phospholipids. Subsequently, the phase transition behavior of the fully hydrated lipid bilayers prepared individually from 11 species of saturated C(X):C(Y)PEth with the same MW was studied by DSC, and the resulting Tm values were codified in terms of the normalized acyl chain asymmetry (deltaC/CL). A V-shaped Tm profile was observed in the plot of Tm versus deltaC/CL for each subclass of these lipids, suggesting two types of packing motif for C(X):C(Y)PEth at T < Tm. Moreover, it was observed that within each packing motif these Tm values were, on average, 2.0 +/- 0.9 degrees C smaller than the Tm values of the corresponding saturated PC. However, based on the unique headgroup conformation of PEth, we were able to predict that monounsaturated PEth with a cis double bond near the H2O/hydrocarbon interface would exhibit a higher Tm than the corresponding PC. Most interestingly, this prediction was indeed borne out by DSC results obtained with C(18):C(20:1delta5)PC and C(18):C(20:1delta5)PEth.

New Insights into the Rh Superfamily of Genes and Proteins in Erythroid Cells and Nonerythroid Tissues

The past decade has seen extensive studies of the erythrocyte Rh30 polypeptides and Rh-associated glycoprotein, which specify the clinically important Rh blood group system. Here we consider recent advances on these and other Rh homologues in the context of gene organization, molecular evolution, tissue-specific expression, protein structure, and potential biological functions. The Rh family is now known to contain a large number of homologues that form a unique branch in the eucarya life domain. The ancient origin and broad distribution imply central roles for the various Rh proteins in maintaining normal cellular and organismal homeostatic conditions. Rh homologues occur in the form of multiple chromosomal loci in mice and humans, but as single-copy genes in unicellular organisms (e.g., green alga and slime mold). While primitive Rh genes vary largely in exon/intron design, the mammalian Rh homologues bear a similar genomic organization. Sequence comparisons have revealed the signatures and a consensus 12-transmembrane fold characteristic of the Rh family. Phylogenetic analysis has placed all Rh homologues as a related cluster that intercepts ammonium transporter (Amt) clusters, indicating an intimate evolutionary and structural relationship between the Rh and Amt families. The biochemical identification and epithelial expression of RhBG and RhCG orthologues in mammalian kidney, liver, skin, testis, and brain suggest that they serve as transporters likely participating in ammonia homeostasis. Further inquires into the structure, function, biosynthesis, and interaction of Rh proteins will shed new light on ammonia homeostasis in a wide range of human physiological and pathological states.

The investigation of three-dimensional vibration for piezoelectric rectangular parallelepipeds using the AF-ESPI method

Electronic speckle pattern interferometry (ESPI) is a powerful tool for the full-field measurement of a deformed body. In this paper, a three-dimensional vibrating block that couples the out-of-plane and in-plane motions is investigated using the amplitude-fluctuation ESPI (AF-ESPI). This method demonstrates the advantages of combining high processing speed, such as in the subtraction method, with high fringe sensitivity, such as in the time-averaged method. The optical system for AF-ESPI is then employed to analyze the volume vibration of piezoelectric material for a rectangular parallelepiped configuration. Based on the fact that fringe patterns measured by the AF-ESPI method appear as a clear picture only at the resonant frequency, both the natural frequencies and the out-of-plane and in-plane vibration mode shapes are successfully obtained in this study. Finally, the impedance analysis as well as the finite element method (FEM) with three-dimensional model are also conducted to compare with the result obtained by AF-ESPI. It is shown that the numerical calculation and the experimental result agree fairly well for both the resonant frequency and the mode shape in three-dimensional configurations.

Enhanced cAMP-induced nitric oxide-dependent coronary dilation during myocardial stunning in conscious pigs

The goal of the current study was to determine the effects of cAMP-mediated coronary reactivity in conscious pigs with stunned myocardium induced by 1.5 h coronary stenosis (CS) and 12 h coronary artery reperfusion (CAR). Domestic swine (n = 5) were chronically instrumented with a coronary artery blood flow (CBF) probe, hydraulic occluder, left ventricular pressure gauge, wall-thickening crystals in the ischemic and nonischemic zones, and a coronary sinus catheter. The hydraulic occluder was inflated to induce a CS with a stable 38 +/- 1% reduction in CBF for 1.5 h. Before flow reduction and during CAR, cAMP-induced coronary vasodilation was investigated by forskolin (20 nmol. kg(-1). min(-1)). Enhanced CBF responses [+62 +/- 9%, P < 0.05, compared with pre-CS (+37 +/- 3%)] were observed for forskolin at 12 h after CAR as well as for bradykinin and reactive hyperemia. With the use of a similar protocol during systemic nitric oxide (NO) synthase inhibition with N(omega)-nitro-L-arginine (30 mg. kg(-1). day(-1) for 3 days), the enhanced CBF responses to forskolin, bradykinin, and reactive hyperemia were not observed after CS. Isolated microvessel preparations from pigs (n = 8) also demonstrated enhanced NO production to direct stimulation of adenylyl cyclase with forskolin (+71 +/- 12%) or NKH-477 (+60 +/- 10%) and administration of 8-bromo-cAMP (+74 +/- 13%), which were abolished by protein kinase A or NO synthase inhibition. These data indicate that cAMP stimulation elicits direct coronary vasodilation and that this action is amplified in the presence of sustained myocardial stunning after recovery from CS. This enhanced cAMP coronary vasodilation is mediated by an NO mechanism that may be involved in myocardial protection from ischemic injury.

The effect of fluvastatin on fibrinolytic factors in patients with hypercholesterolemia

Several studies have shown cardiovascular benefit in treating hypercholesterolemia with HMG-CoA reductase inhibitor. However, in addition to the lowering of cholesterol, the beneficial effects of this inhibitor reflect other pharmacological activities. Whether these beneficial effects are partly mediated by changes in fibrinolytic factors remains to be proven, since clinical studies on the effects of HMG-CoA reductase inhibitors on fibrinolytic factors have not yielded consistent results. The purpose of this study was to evaluate the effects of fluvastatin on fibrinolytic factors in hypercholesterolemic patients. After 6 weeks on a low-fat, low-cholesterol diet, 23 outpatients known to have primary hypercholesterolemia with low density lipoprotein cholesterol (LDL-C) > or = 130 mg/dl with at least 2 risk factors or fasting LDL-C > or = 160 mg/dl were selected for the study. Venous blood samples were collected at baseline and at 8 weeks after fluvastatin therapy (40 mg/day) to measure of tissue plasminogen activator (t-PA), plasminogen activators inhibitor-1 (PAI-1), fibrinogen, D-dimer and lipid profile. After 8 weeks of therapy, fluvastatin reduced serum cholesterol by 11% (261.9 mg/dl vs 233.2 mg/dl, P < 0.01) and LDL-C by 22% (191.9 mg/dl vs 149.3 mg/dl, P < 0.01). D-dimer was significantly decreased (0.38 ng/L vs 0.28 ng/L, P = 0.02) and tPA, PAI-1 and fibrinogen tended to decrease after therapy. Fluvastatin therapy improved fibrinolytic profile; the result of this study may in part explain the benefit of HMG-CoA reductase inhibitor on cardiovascular system other than lipid lowering.

Characterization of an axonemal dynein heavy chain expressed early in airway epithelial ciliogenesis

The most conspicuous evidence of airway epithelial maturation and vitality is the presence of motile cilia. In an effort to generate genetic and antigenic markers of airway maturation, injury, and repair, we characterized airway epithelial expression of a gene identified by two human expressed sequence tags that encoded peptides with sequence similarity to an invertebrate ciliary dynein heavy chain (DHC). Molecular analyses showed that the gene has a very large RNA transcript that encodes a very high molecular weight polypeptide with biochemical properties that are characteristic of a dynein heavy chain. Expression of the gene transcript correlated with the presence of ciliated cells in tissues, and immunohistochemical localization of the gene product confirmed its presence in the cilia of mature airway epithelium. In epithelium undergoing ciliogenesis ex vivo, expression of the gene transcript preceded ciliation of the epithelium and the gene product was present in the cytoplasm and at the apical border of nonciliated cells. These data suggested that the gene encodes an axonemal DHC that is expressed early during ciliogenesis, before the appearance of cilia.

Genetic aberration in primary hepatocellular carcinoma: correlation between p53 gene mutation and loss-of-heterozygosity on chromosome 16q21-q23 and 9p21-p23

To elucidate the molecular pathology underlying the development of hepatocellular carcinoma (HCC), we used 41 highly polymorphic microsatellite markers to examine 55 HCC and corresponding non-tumor liver tissues on chromosome 9, 16 and 17. Loss-of-heterozygosity (LOH) is observed with high frequency on chromosomal region 17p13 (36/55, 65%), 9p21-p23 (28/55, 51%), 16q21-q23 (27/55, 49%) in tumors. Meanwhile, microsatellite instability is rarely found in these microsatellite loci. Direct sequencing was performed to detect the tentative mutation of tumor suppressor genes in these regions: p53, MTS1/p16, and CDH1/E-cadherin. Within exon 5-9 of p53 gene, 14 out of 55 HCC specimens (24%) have somatic mutations, and nucleotide deletion of this gene is reported in HCC for the first time. Mutation in MTS1/p16 is found only in one tumor case. We do not find mutations in CDH1/E-cadherin. Furthermore, a statistically significant correlation is present between p53 gene mutation and loss of chromosome region 16q21-q23 and 9p21-p23, which indicates that synergism between p53 inactivation and deletion of 16q21-q23 and 9p21-p23 may play a role in the pathogenesis of HCC.

Functional implication of human serine/threonine kinase, hAIK, in cell cycle progression

Protein phosphorylation is involved in many biological activities and plays important roles in cell cycle progression. In the present study, we identified a serine/threonine kinase, hAIK, from human hepatic cells using degenerated polymerase chain reactions with a pair of primers derived from the highly conserved sequence in the catalytic domain of kinases. The full-length hAIK cDNA was then obtained, which contained 403 amino acids and was homologous to Drosophila Aurora2 and yeast Ipl1 proteins. Northern blotting analysis revealed that hAIK was highly expressed in the testis but not in other tissues. Expressions of hAIK drastically increased in cancer tissues/cell lines but not in fibroblasts or nontumorigenic cell lines. The recombinant hAIK protein phosphorylated itself and histone H1; this phosphorylation activity was totally abolished after a point mutation at the catalytic domain (hAIKm). During the interphase cell, hAIK was found mainly in the cytoplasm; during mitosis hAIK accumulated at the centrosomes. In addition, overexpression of hAIK in cancer cell lines (HEK293T and HeLa) appeared to inhibit cell cycle progression. None of these phenomena were observed in hAIKm whose kinase activity was rendered inactive. Our results suggest that hAIK protein/activity might modulate cell cycle progression by interacting with the centrosomes and/or proteins associated with these structures.

Photoelectrochemical Response of Langmuir-Blodgett Monolayer Films Containing Donor-pi-Acceptor Azomethine Dyes

Three amphiphilic azomethine dyes, (E)-N-octadecyl-2-[2-(4-N, N-dimethylaminophenyl)azomethinyl]quinolinium tiodide, (E)-N-octadecyl-4-[2-(4-N, N-dimethylaminophenyl)azomethinyl]quinolinium iodide, and (E)-N-octadecyl-6-[2-(4-N, N-dimethylaminophenyl)azomethinyl]quinolinium iodide, have been prepared by changing different relative positions of electron-accepting groups. They were successfully transferred onto indium-tin oxide slides by the Langmiur-Blodgett (LB) technique. Photoelectrochemical studies on these dyes' LB monolayer-modified ITO electrode were carried out. In 0.5 M KI solution containing 0.05 M I(2), the photocurrent generation quantum yield for these dyes varied from 7.2 to 15.9%, depending on the linking positions. Dependence of the photocurrent on the applied potential and the redox couple suggests that they undergo the photoinduced electron transfer mechanism of photoelectric conversion. Copyright 2000 Academic Press.