Altered nociceptive response in mice deficient in the alpha(1B) subunit of the voltage-dependent calcium channel

Calcium influx through N-type calcium channels mediates synaptic transmission at numerous central synapses and transduces nociceptive information in the spinal dorsal horn. However, the precise role of N-type calcium channels in pain perception is not fully elucidated. To address this issue, we generated and analyzed knockout mice for alpha(1B,) the pore-forming subunit of the N-type calcium channel. Homozygous mutants are viable, fertile, and show normal motor coordination. In small-diameter dorsal root ganglion neurons from mutants the density of calcium channel currents is significantly reduced, which can be accounted for by the abolition of N-type currents. We performed several pain-related behavioral tests using the mutant mice. alpha(1B)-Deficient mice show reduced response to mechanical stimuli in the von Frey test and increased tail flick latency in response to radiant heat, indicating altered spinal reflexes. However, pain response in the hot plate test is normal. In the formalin paw test, the mutant mice exhibit significantly attenuated response in Phase 2, but normal pain behaviors in Phase 1. The response to visceral inflammatory pain caused by acetic acid is also reduced in alpha(1B) knockout mice. These results suggest that the alpha(1B) subunit of N-type calcium channel plays a major role in pain perception by acting at the spinal level, but not at the supraspinal level.

Expression profile of nine novel genes differentially expressed in hepatitis B virus-associated hepatocellular carcinomas

Chronic hepatitis B virus (HBV) infection is known to be one of the major causes in the development of hepatocellular carcinoma (HCC), although the biomolecular mechanism(s) involved remain unclear. To identify the cellular gene(s) involved in HBV-associated hepatocarcinogenesis, we used the mRNA differential display method and examined three paired tumor and nontumor tissues, all of which had chromosomally integrated HBV-DNA through chronic infection. Using 240 different combinations of three one-base anchored oligo-dT primers and 80 arbitrary 13-mers, genes decreased or increased in expression more than twofold between each tumor tissue and its paired nontumor tissue were identified. Twenty-nine known genes and four novel genes were differentially over-expressed in the HCC tumor tissues. In contrast, 27 known genes and five novel genes were under-expressed in those tumor tissues. The nucleotide sequences of the nine novel gene fragments were determined and their expression patterns were examined in 40 HCC samples. HA61T2, PT18, HG63T1, and HG57T1 were preferentially over-expressed in 32 cases (80%, P<0.001), 24 cases (60%), 23 cases (57.5%) and 22 cases (55%) of the 40 tumor tissues, respectively. There was an increased frequency of HG57T1 over-expression in HCC patients with HBV-positive serology and low serum alpha-feto protein (AFP) levels (P<0.05). DNT10, PT8, PT19, ENT25 and HA6T4 were under-expressed in 26 cases (65%), 23 cases (57.5%), 21 cases (53%), 20 cases (50%) and 18 cases (45%) of the 40 tumor samples, respectively. There was a strong correlation of DNT10 under-expression with high serum AFP level in HCC patients, irrespective of HBV serology (P<0.01). HA6T4 was preferentially under-expressed in HCC tumors in patients with HBV-positive serology and high serum AFP levels (P<0.05). Thus, the functional analyses of the known and novel genes identified in this study should prove valuable to further understand the mechanism(s) of hepatocarcinogenesis.

Lack of the burst firing of thalamocortical relay neurons and resistance to absence seizures in mice lacking alpha(1G) T-type Ca(2+) channels

T-type Ca(2+) currents have been proposed to be involved in the genesis of spike-and-wave discharges, a sign of absence seizures, but direct evidence in vivo to support this hypothesis has been lacking. To address this question, we generated a null mutation of the alpha(1G) subunit of T-type Ca(2+) channels. The thalamocortical relay neurons of the alpha(1G)-deficient mice lacked the burst mode firing of action potentials, whereas they showed the normal pattern of tonic mode firing. The alpha(1G)-deficient thalamus was specifically resistant to the generation of spike-and-wave discharges in response to GABA(B) receptor activation. Thus, the modulation of the intrinsic firing pattern mediated by alpha(1G) T-type Ca(2+) channels plays a critical role in the genesis of absence seizures in the thalamocortical pathway.

Deficient long-term synaptic depression in the rostral cerebellum correlated with impaired motor learning in phospholipase C beta4 mutant mice

Long-term depression (LTD) at parallel fibre-Purkinje cell synapse of the cerebellum is thought to be a cellular substrate for motor learning. LTD requires activation of metabotropic glutamate receptor subtype 1 (mGluR1) and its downstream signalling pathways, which invariably involves phospholipase Cbetas (PLCbetas). PLCbetas consist of four isoforms (PLCbeta1-4) among which PLCbeta4 is the major isoform in most Purkinje cells in the rostral cerebellum (lobule 1 to the rostral half of lobule 6). We studied mutant mice deficient in PLCbeta4, and found that LTD was deficient in the rostral but not in the caudal cerebellum of the mutant. Basic properties of parallel fibre-Purkinje cell synapses and voltage-gated Ca2+ channel currents appeared normal. The mGluR1-mediated Ca2+ release induced by repetitive parallel fibre stimulation was absent in the rostral cerebellum of the mutant, suggesting that their LTD lesion was due to the defect in the mGluR1-mediated signalling in Purkinje cells. Importantly, the eyeblink conditioning, a simple form of discrete motor learning, was severely impaired in PLCbeta4 mutant mice. Wild-type mice developed the conditioned eyeblink response, when pairs of the conditioned stimulus (tone) and the unconditioned stimulus (periorbital shock) were repeatedly applied. In contrast, PLCbeta4 mutant mice could not learn the association between the conditioned and unconditioned stimuli, although their behavioural responses to the tone or to the periorbital shock appeared normal. These results strongly suggest that PLCbeta4 is essential for LTD in the rostral cerebellum, which may be required for the acuisition of the conditioned eyeblink response.

The biological significance of phospholipase C beta 1 gene mutation in mouse sperm in the acrosome reaction, fertilization, and embryo development

PURPOSE

We carried out this study to evaluate the biological significance of phospholipase C beta 1 gene mutation in mouse sperm in the acrosome reaction, fertilization, and embryo development.

METHODS

Study subjects were divided into two groups according to the sperm [intact phospholipase C (PLC) beta 1 and PLC beta 1-/- C57BL/6J x CBA F1 mouse sperm] used. The positive acrosome reaction rate labeled with fluorescein isothiocyanate-Pisum sativum agglutinin, the fertilization rate, and the rate of embryos developed to the stage of morula or blastocyst in the two groups were compared.

RESULTS

The mouse sperm null for the PLC beta 1 gene showed a lower acrosome reaction rate than control sperm (69.2 vs 50.9%, P < 0.05). And the fertilization rate and the rate of embryos developed to the stage of morula or blastocyst were also lower in the group using PLC beta 1-/- mouse sperm compared to the intact group (P < 0.05; 73.5 vs 51.8% and 15.7 vs 4.3%, respectively).

CONCLUSIONS

Mutation of the PLC beta 1 gene in the mouse sperm reduces the acrosome reaction rate, fertilization rate, and embryo development rate, which may be the etiologic factors responsible for the low reproductive rate of PLC beta 1-/- mouse.

Sensitive determination of bisphenol A in environmental water by gas chromatography with nitrogen-phosphorus detection after cyanomethylation

A new technique is proposed for the determination of bisphenol A in environmental water. The sample preparation consists of a single-step extraction of bisphenol A from a water sample with methylene chloride and the cyanomethyl derivatization of bisphenol A. 2,2'-Biphenol is used as an internal standard. Bisphenol A and biphenol can be quantitatively converted to their corresponding cyanomethyl ethers, which are then measured by gas chromatography with nitrogen-phosphorus detection. Peak shape and quantification of bisphenol A are excellent, with linear calibration curves over a range of 0.1-100 ng/ml. The detection limit is 0.1 ng/ml in water samples. The average recovery and RSD at a concentration of 5 ng/ml are 89.3 and 4.5%, respectively. The procedure is applicable to the quantification of bisphenol A in tap water, raw water and stream water.

PLC-beta1, activated via mGluRs, mediates activity-dependent differentiation in cerebral cortex

During development of the cerebral cortex, the invasion of thalamic axons and subsequent differentiation of cortical neurons are tightly coordinated. Here we provide evidence that glutamate neurotransmission triggers a critical signaling mechanism involving the activation of phospholipase C-beta1 (PLC-beta1) by metabotropic glutamate receptors (mGluRs). Homozygous null mutation of either PLC-beta1 or mGluR5 dramatically disrupts the cytoarchitectural differentiation of 'barrels' in the mouse somatosensory cortex, despite segregation in the pattern of thalamic innervation. Furthermore, group 1 mGluR-stimulated phosphoinositide hydrolysis is dramatically reduced in PLC-beta1-/- mice during barrel development. Our data indicate that PLC-beta1 activation via mGluR5 is critical for the coordinated development of the neocortex, and that presynaptic and postsynaptic components of cortical differentiation can be genetically dissociated.

Multi-step sequential batch two-phase anaerobic composting of food waste

This study was conducted to evaluate the newly devised process, called MUlti-step Sequential batch Two-phase Anaerobic Composting (MUSTAC). The MUSTAC process consisted of several leaching beds for hydrolysis, acidification and post-treatment, and a UASB reactor for methane recovery. This process to treat food waste was developed with a high-rate anaerobic composting technique based on the rate-limiting step approach. Rumen microorganisms were inoculated to improve the low efficiency of acidogenic fermentation. Both two-phase anaerobic digestion and sequential batch operation were used to control environmental constraints in anaerobic degradation. The MUSTAC process demonstrated excellent performance as it resulted in a large reduction in volatile solids (VS) (84.7%) and high methane conversion efficiency (84.4%) at high organic loading rates (10.8 kg VS m(-3) d(-1)) in a short SRT (10 days). Methane yield was 0.27 m3 kg(-1) VS, while methane gas production rate was 2.27 m3 m(-3) d(-1). The output from the post-treatment could be used as a soil amendment, which was produced at the same acidogenic fermenter without troublesome moving. The main advantages of the MUSTAC process were simple operation and high efficiency. The MUSTAC process proved stable, reliable and effective in resource recovery as well as waste stabilization.

Effect of carbohydrate and protein in the EPS on sludge settling characteristics

EPSs have been believed to play a bonding role in microbial floc formation. However, the precise role is not well known. In this study, sludge settling characteristics and the carbohydrate to protein ratio in the EPS were tested at various airflow rates. Sludge was collected from three modified sequencing batch reacetors (MSBRs), which were operated with airflow rates of 0.8 L/min, 2 L/min and 4 L/min, respectively. During the operation periods, the reactor operated at an airflow rate of 0.8 L/min showed a sludge volume index (SVI) of 80 to 90 mL/g and a constant ratio of carbohydrate to protein in the EPS, while a significant increase of this ratio and the SVI occurred in the other reactors. High airflow rate increased the amount of carbohydrate in the EPS, but the protein level was almost constant for reactors with airflow rates of 2 L/min and 4 L/min. The higher ratio of carbohydrate to protein caused the bulking of the sludge; hence it was not favourable for sludge settling. The ratio of carbohydrate and protein in the EPS is inferred to be essential for solid floc formation.

Chemical characteristics and leachability of organically contaminated heavy metal sludge solidified by silica fume and cement

This paper discusses the development of mixtures with silica fume as a stabilization/solidification agent and binder for industrial wastewater residue containing organic and heavy metal contaminants. The UCS (Unconfined Compressive Strength) gradually increased to 66.7% as the silica fume content increased to 15%. The leaching of TOC and chromium decreased as more OPC was substituted with silica fume. When the mix had 5% silica fume, it retained about 85% TOC, and chromium leached out 0.76 mg-Cr/g-Cr in acidic solution. Also, microstructural studies on the solidified wastes through the scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) and X-ray diffraction analysis showed that the silica fume caused an inhibition to the ettringite formation which did not contribute to setting, but coated the cement particles and retarded the setting reactions. The results indicated that the incorporation of silica fume into the cement matrix minimized the detrimental effects of organic materials on the cement hydration reaction and contaminant leachability.

Pretreatment of whole blood for use in immunochromatographic assays for hepatitis B virus surface antigen

Immunochromatographic assays (ICAs) are also referred to as rapid tests, since they are simple and the results can be obtained within minutes after manually loading a few drops of a sample into each sample well of the test device. However, whole blood cannot be tested with ICA kits due to the visual hindrance caused by the color of red blood cells (RBCs), unless a cell-removing device such as a filter is mounted on the kits. Thus, when testing with blood, the advantage of the ICA kit is lost because of the additional time and machines required to coagulate and separate whole blood before preparing the serum. To overcome this limitation, whole-blood samples were added to a pretreatment solution to decolor the RBCs; the resulting mixtures were then loaded into the sample wells of the test device. The pretreating solution was composed of hydrogen peroxide (H(2)O(2)) to decolor the RBCs, Sag 471 (Osi Specialties) to restrain the mixture from vigorous foaming, sodium azide (NaN(3)) to inhibit the enzyme, which generates excessive foam at the beginning of decolorization, and EDTA as a chelating agent. As a result of this pretreatment, whole blood could be used with the ICA kit without reducing its simplicity and rapidity.

Concentrations and activity ratios of uranium isotopes in the groundwater of the Okchun Belt in Korea

Groundwater samples obtained from the Okchun Belt in Korea were separated into particulate and filtered fraction using a 0.45 microm membrane filter and concentrations and activity ratios of uranium isotopes in the fractions were determined by chemical separation and alpha-spectrometric measurements. Most of the uranium isotopes in the groundwater were found in the filtered water. Only less than 1% of the total uranium was detected in the particulate fraction. The concentrations and activity ratios of uranium isotopes in the groundwater measured in this study were variable, depending upon sampling site. Owing to a rapid material exchange between the subterranean hot waters and the rock strata, the concentrations of 238U in the groundwater in the hot spring area were found to be about four times higher than those elsewhere. Because of the alpha-particle recoil effect, the activity ratios of 234U/238U in the groundwater taken at "cold" spring sites were variable within the range 1.20 to 3.58, depending on the residence time of the groundwater. In the hot spring area, the activity ratios of 234U/238U were close to the equilibrium value (1.10 +/- 0.07) due to rapid erosion of the rock strata by the hot spring water.

The Na+ -Ca2+ exchanger is essential for embryonic heart development in mice

The cardiac Na+ -Ca2+ exchanger 1 (NCX1) is thought to be the major calcium extrusion mechanism and to play an important role in the regulation of intracellular calcium in the heart. The Na+ -Ca2+ exchanger is particularly abundant in the heart, although it is found in a variety of other tissues. To investigate the role of NCX1, we have generated NCX1-deficient mice. Mice heterozygous for the NCX1 mutation showed no discernable phenotype, grew normally, and were fertile; however, no viable homozygote was observed among 175 offspring obtained from intercrosses of heterozygotes. All the homozygous mutant mice died in utero before E10.5. Morphological analysis indicated that homozygotes of NCX1 mutation at E9.5 died with an underdeveloped heart with a dilated pericardium. Microscopic analysis of these embryos showed myocardial cell loss due to apoptosis. The apoptosis was first observed in E8.5 mutant heart. Areas outside the heart appeared normal in the mutant embryos at E8.5. In contrast, at E9.0, various regions of mutant embryos showed extensive cell loss. These results suggest that mutant embryos die owing to cardiac abnormalities caused by apoptotic cell loss, indicating that NCX1 is essential for normal development of the heart.

Sweet's syndrome with abscess-like lesions in a patient with acute myelogenous leukemia

We describe a 49-year-old man with acute myelogenous leukemia associated with Sweet's syndrome and abscess-like lesions mimicking an infectious disease. Although blisters may be included in the clinical spectrum, frank non-infectious abscesses have not been reported as far as we know. Clinicians should be familiar with this clinical and histopathologic variant of Sweet's syndrome. It is mandatory to make every effort to find an infectious cause for abscesses before a diagnosis of Sweet's syndrome is made.

Insertion of a retroviral solo long terminal repeat in mdr-3 locus disrupts mRNA splicing in mice

Previously, the abermectin-induced neurotoxicity of subpopulation of CF-1 mice was shown to be caused by the deficiency of mdr-3 P-glycoprotein. Here, we have characterized the molecular nature of the mdr-3 gene mutation in this subpopulation of CF-1 mice. The size of mdr-3 mRNA transcript from ivermectin-sensitive mutant mice was different from that of wild-type mice. Sequence analysis of RT-PCR products isolated from the mutant brain disclosed that the exon 23 of the mdr-3 gene is deleted or altered in the transcripts. The analysis of the genomic locus revealed an insertion of a solo long terminal repeat (LTR) of the ecotropic murine leukemia virus in the reverse orientation in the intron of the mdr-3 gene, causing abnormal splicing and thereby disrupting the mdr-3 gene function. In addition, histopathological analysis of the brains of the ivermectin-treated mutants revealed selective neuronal degeneration in the hippocampal CA3 region. This is the first reported case of a gene mutation induced by a solo retroviral LTR with a phenotypic consequence in the mouse, and may provide new insights into the understanding of the effects of viral solo LTR sequences on mammalian gene expression.

Immunological characterization of 130 kDa phospholipase C-beta 4 isozyme in rat cerebellar Purkinje cells

We have developed a monoclonal antibody, beta4-22-9 that recognizes an epitope on pleckstrin homology (PH) domain (1-136 amino acids) located at the amino terminus of rat 130 kDa phospholipase C-beta4 (PLC-beta4). Tissue distribution of 130 kDa PLC-beta4 was determined with this monoclonal antibody. One hundred and thirty kiloDalton PLC-beta4 was exclusively expressed in the nervous tissues including cerebellum and cerebrum, especially at very high levels in cerebellum. The expression of 130 kDa PLC-beta4 in cerebellum was gradually increased from 5 days after birth to adulthood. In the adult cerebellum, especially high level of 130 kDa PLC-beta4 was localized on the periphery of Purkinje cells in the patch-like pattern. These data implies that 130 kDa PLC-beta4 may a role in cerebellar Purkinje cells.

Identity of mouse IA-2 and PTP35 genes of the tyrosine phosphatase family, and their expression in neuroendocrine tissues

Recently, IA-2, one of the major diabetic autoantigens, and PTP35 cDNA were independently isolated by subtraction cloning using insulinoma cells and a polymerase chain reaction (PCR)-based search for conserved sequences using NIH3T3 fibroblast cell line, respectively. By Southern blot analysis and nucleotide sequence determination of reverse transcription PCR products, we showed that IA-2 and PTP35 are identical and exist as a single gene in a mouse genome. The expression of IA-2/PTP35 messages was detected by northern blot analysis in MIN6N8 cells, an insulinoma cell line derived from non-obese diabetic mice, but its expression level was not affected by the ambient glucose level, phorbol-12-myristate 13-acetate or tumour necrosis factor-alpha. We also generated polyclonal antibodies to murine IA-2/PTP35 by immunization with recombinant proteins. Subsequent immunohistochemical analysis using these polyclonal antibodies disclosed that IA-2/PTP35 is strongly expressed in mouse neuroendocrine tissues such as pancreatic islets and the hypothalamus-pituitary gland. These results suggest that IA-2/PTP35 functions primarily in neuroendocrine tissues.

Stereoselective metabolism of famprofazone in humans: N-dealkylation and beta- and p-hydroxylation

Following administration of famprofazone to humans, the stereoselective metabolism from the drug to its known metabolites (+,-)-ephedrine, (+,-)-pseudoephedrine, (+,-)-norephedrine, (+,-)-norpseudoephedrine, (+,-)-p-hyroxyamphetamine, (+,-)-p-hydroxymethamphetamine, and (+,-)-p-hydroxynorephedrine was studied. The enantiomers of the metabolites were derivatized with alpha-methoxy-alpha -(trifluoromethyl)-phenylacetyl chloride (MPTA.Cl) as the chiral derivatizing agent for amino groups and N-methyl-N-trimethylsilyl trifluoroacetamide (MSTFA) or N-methyl-N-triethylsilyl trifluoroacetamide (MTESTFA) as protecting agents of the hydroxyl groups. The diastereomeric derivatives were well separated by capillary gas-liquid chromatography and determined by mass spectrometry with selected-ion monitoring (SIM). (-)-Methamphetamine, (-)-amphetamine, (-)-p-hydroxyamphetamine, and (-)-p-hydroxymethamphetamine were exerted in greater amounts than their enantiomers after administration of racemic famprofazone; and (-)-ephedrine, (-)-pseudoephedrine, (-)-norephedrine, and (-)-norpseudoephedrine were found in higher concentration than their enantiomers. Famprofazone was metabolized by product and substrate stereoselective N-dealkylation, beta-hydroxylation, and p-hydroxylation, metabolites of which may be predominantly responsible for the side effects of famprofazone.

Regulation of phospholipase C-beta 3 activity by Na+/H+ exchanger regulatory factor 2

Among the phospholipase C that catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphate, four mammalian phospholipase C-beta (PLC-beta) isotypes (isotypes 1-4) are activated through G protein-coupled receptors (GPCRs). Although the regulation of the PLC-betas by GPCRs and heterotrimeric G proteins has been extensively studied, little is known about the molecular determinants that regulate their activity. The PLC-beta isozymes carry a putative PSD-95/Dlg/ZO-1 (PDZ) binding motif (X(S/T)X(V/L)COOH) at their carboxyl terminus, which is implicated in specific interactions with anchor proteins. Using the yeast two-hybrid system, we identified Na(+)/H(+) exchanger regulatory factor 2 (NHERF2) as a protein that interacted with a C-terminal heptapeptide of PLC-beta3. Immunoprecipitation studies revealed that NHERF2 interacts specifically with PLC-beta3, but not with other PLC-beta isotypes. Furthermore, PLC-beta3 interacted with NHERF2 rather than with other PDZ-containing proteins. This interaction required the COOH-terminal NTQL sequence of PLC-beta3 and the second PDZ domain of NHERF2. Interestingly, NHERF2 potentiated the PLC-beta activation by carbachol in COS7 and HeLa cells, while mutant NHERF2, lacking the second PDZ domain, had no such effect. Taken together, the data suggest that NHERF2 may act as a modulator underlying the process of PLC-beta3-mediated signaling.

Ciliated foregut cyst of the gallbladder: a case report and review of the literature

A case is presented of a ciliated cyst of the gallbladder in a 36-year-old Korean woman which was incidentally found on ultrasonographic study. A cystic mass measuring 1.5 x 1 x 1 cm was found in the fundus of the gallbladder. The cyst was unilocular and intramural without communication to the lumen. Microscopically, the cyst wall was lined by a single layer of pseudostratified, ciliated, columnar epithelium and goblet cells with underlying smooth muscle layers. This was considered to be the cyst arising from the embryonic foregut and showing differentiation toward respiratory structures. The term 'ciliated foregut cyst of the gallbladder' is suggested here.

General pharmacology of the new antiviral agent SK 1899

The general pharmacological properties of 2-amino-9-(3-acetoxymethyl-4-isopropoxycarbonyloxybut-1-yl)purine (CAS 247081-81-8, SK 1899), a new potential antiviral agent, were investigated in mice, rats, guinea pigs, rabbits, and dogs. The oral administration of 50, 150, and 500 mg/kg of SK 1899 had no effects on the central nervous system except that it slightly increased the spontaneous locomotor activity in mice at a dose of 500 mg/kg. SK 1899 did not disturb either the spontaneous motility or contractor-induced contraction of the isolated organs such as guinea pig ileum, rat uterus, guinea pig vas deferens, and guinea pig trachea at concentrations up to 10(-4) mol/l. It slightly increased the contractile force in the isolated guinea pig atrium at a concentration of 10(-4) mol/l. Following intravenous infusion of 5, 15, and 50 mg/kg of SK 1899 to anesthetized dogs, it did not change the mean arterial pressure, heart rate, left ventricular systolic pressure (LVSP), and respiratory rate, while it slightly increased the left ventricular positive dP/dtmax (LV + dP/dtmax) at a dose of 50 mg/kg. SK 1899 did not induce any significant changes in the intestinal charcoal meal transit in mice, basal gastric juice secretion in rats, and renal function in rats. It did not affect the blood coagulation system and phenolsulfonphthalein secretion in rats. These findings suggest that SK 1899 has a very low potential to induce any adverse pharmacological effects at the doses showing antiviral activity.

Reduced expression of the cell-cycle inhibitor p27Kip1 is associated with progression and lymph node metastasis of gastric carcinoma

AIMS

p27Kip1 (p27), a cyclin-dependent kinase inhibitor, plays an important role as inhibiting the progression of the cell cycle. Decreased expression of p27 is associated with high histological grade and aggressiveness of several human tumours. We aimed to evaluate the role of p27 in the progression and metastasis of gastric carcinoma.

METHODS AND RESULTS

We analysed the expression of p27 in 67 primary gastric carcinomas and 31 lymph node metastases by immunohistochemistry. Reduced expression of p27 was found more frequently in advanced gastric cancer (40.9%) than in early gastric cancer (15.6%) (P < 0.001). Decreased p27 expression correlated with large tumour size, high histological grade, lymphatic invasion, advanced stage, deep invasion, lymph node metastasis and recurrence. The expression of p27 showed an inverse correlation with the Ki67 labelling index. There was a significant reduction of p27 expression in metastatic tumour cells in lymph nodes (mean positive cells: 3. 7%) when compared to the corresponding primary gastric carcinomas (mean positive cells: 8.1%) (P = 0.008).

CONCLUSIONS

Alterations of p27 expression may play an important role in the progression and metastasis to lymph node of tumour cells in human gastric carcinoma.