Acute pancreatitis complicated by infarction of the spleen and spinal cord

Complications of acute pancreatitis may include local pancreatic necrosis with pseudocyst or abscess formation, and extrapancreatic manifestations such as pulmonary renal, hepatic, endocrine, and coagulation abnormalities. Coagulation abnormalities associated with acute pancreatitis usually present as thrombophlebitis or widespread microthrombi; most occur in the venous or capillary circulation. We report a rare case of acute pancreatitis complicated by pseudocyst formation, splenic vein thrombosis, splenic infarction, and spinal cord infarction, which resulted in paraplegia. An association between acute pancreatitis and spinal cord infarction has not been reported before.

Biometry and primary angle-closure glaucoma among Chinese, white, and black populations

PURPOSE

Primary angle-closure glaucoma (PACG) is more prevalent among Chinese than whites. The authors tested the hypothesis that Chinese have shallower anterior chambers than do whites, a factor that may be related to PACG prevalence.

METHODS

The authors compared anterior chamber depth, axial length, radius of corneal curvature, and refractive error among 531 Chinese, 170 whites, and 188 blacks older than 40 years of age using the same model of instruments and identical technique.

RESULTS

Mean anterior chamber depth and axial length did not differ significantly for the three groups. Whites had a significantly higher prevalence of hyperopia > 2 diopters than did Chinese. Radius of corneal curvature was significantly smaller among Chinese than whites or blacks.

CONCLUSIONS

These results suggest that Chinese do not differ on a population basis from other ethnic groups in many of the biometric risk factors known to be of importance for PACG. It will be necessary to identify other ocular biometric parameters to explain the excess burden of PACG among Chinese, which may improve the effectiveness of screening for this disease in all populations.

Enhancement of immunohistochemical detection of HIV-1 p24 antigen in brain by tyramide signal amplification

Human immunodeficiency virus type 1 (HIV-1) infection of the brain has been demonstrated in formalin fixed, paraffin embedded post-mortem brain tissue (PM) by chromogenic immunohistochemistry for the HIV p24 antigen. The sensitivity of antigen detection is increased significantly by tyramide signal amplification (TSA) compared to the conventional peroxidase labelled Avidin-Biotin complex (ABC) technique. The TSA method also permitted the use of a lower concentration of primary antibody than is conventionally used. Sensitivity was enhanced further by microwave irradiation of the paraffin embedded tissues in citrate buffer. HIV-1 p24 antigen was also detected in PM brain tissue by TSA enhanced immunofluorescence and demonstrated increased sensitivity compared to the conventional immunofluorescence technique with a greatly reduced autofluorescence background.

Genetic analysis of the cytotoxin-associated gene and the vacuolating toxin gene in Helicobacter pylori strains isolated from Taiwanese patients

OBJECTIVE

Two virulence factors encoded by the cytotoxin-associated (cagA) gene and the vacuolating toxin (vacA) gene of Helicobacter pylori are known to be associated with gastroduodenal pathologic conditions. In this report, nucleotide sequence of cagA and vacA and the serum antibody response to the CagA antigen in H. pylori isolates from Taiwanese patients were studied.

METHOD

cagA and vacA were characterized in 173 H. pylori strains by polymerase chain reaction and DNA hybridization analyses. The presence of serum IgG antibodies against CagA was assessed by Helico-blot Western blot system. Sequence analysis of polymerase chain reaction-amplified vacA and cagA was performed for two strains.

RESULTS

cagA was detected in all the isolates with peptic ulcers and gastric cancer. Of 54 strains with non-ulcer dyspepsia, 51 were found to be cagA+. Serum antibodies to CagA were detected for 99.2% of cagA+ strains compared with 0% of strains lacking cagA. vacA was detected in all isolates. Sequence analysis of vacA and cagA indicated that sequences of two Taiwanese strains were closely related to each other (95.9% and 97% nucleotide identity, respectively) but less homologous to the published strains (90.9% and 91.4% mean nucleotide sequence identity, respectively).

CONCLUSIONS

The strong association (98%) of cagA+ strains with Taiwanese patients suggests that the cagA+ phenotype could not be used as a single marker of high-risk patients in Taiwan. Moreover, sequence analysis indicates that Taiwanese strains contain different genetic sequences from those in other geographic regions.

Characterization of Ca(2+)- and voltage-dependent nonselective cation channels in human HepG2 cells

Nonselective cation channels have been identified and linked to important cell functions in rat hepatocytes. In this study, we characterized inward rectifying nonselective cation channels in detail by the patch clamp technique in human HepG2 cells. Channel properties were studied with high resistance borosilicate pipettes in cell-attached and inside-out configurations. With Ringer's solution and KCl as pipette solutions, the conductances were 19.7 +/- 2.1 and 22.2 +/- 0.0 picosiemens (pS), and reversal potentials were 30.9 +/- 3.5 and 31.3 +/- 4.6 mV, respectively. The channel was permeable to Ba2+, and the sequence of permeability ratios was Na+ > K+ > Cs+ > Ba2+. In the cell-attached configuration, the channel had a higher opening probability at depolarizing potential than at hyperpolarizing. In the inside-out patches with symmetric Ringer's solution, the current voltage curve was linear with conductance of 19.8 +/- 0.9 pS. Reversal potential shifted from -0.2 +/- 1.0 mV to 23.2 +/- 1.0 mV when the bath solution was replaced by dilute Ringer's solution. In the inside-out configuration, the gating was Ca(2+)-dependent, and the opening probability increased with increasing intracellular calcium concentration ([Ca2+]i). An outward rectifying channel appeared when [Ca2+]i was less than 1 mumol/L. The nonselective channel was reversibly blocked by 10 mumol/L internal flufenamic acid. We conclude that Ca(2+)- and voltage-dependent nonselective cation channels are present in human HepG2 cells. The channels might be involved in the regulation of Ca2+ influx and are associated with activation of other ion channels.

Automated perimetry in primary open-angle glaucoma

Primary open-angle glaucoma (POAG) is one of the leading causes of blindness worldwide. Patients are usually asymptomatic until severe anatomic and functional damage occurs. Visual field examination is important in managing glaucoma patients, especially in the treatment and follow-up of moderate to advanced cases. This study was designed to investigate the patterns of automated visual field defects in POAG. We studied 296 POAG patients from the Glaucoma Clinic of the National Taiwan University Hospital from January 1986 to June 1996. The perimetry was performed using the Octopus program 32 or 38, or Humphrey program 30-2, and the results were analyzed according to the Glaucoma Hemifield Test design. The depth and frequency of locations of visual field defects were computed, and stratified by age and intraocular pressure (IOP). The results suggested that the most frequently affected locations in POAG were paracentral areas, while the deepest scotoma appeared in the upper and lower nasal areas. Patients with IOP higher than 25 mmHg or older than 50 years had higher mean sensitivity losses in both superior and inferior hemifields. The results of this study revealed the patterns of automated visual field defects in POAG may be a useful guide for the management of POAG patients.

Increased prevalence of Helicobacter pylori infection among patients affected with intestinal-type gastric cancer at non-cardiac locations

Previous data on the association of Helicobacter pylori infection with gastric cancer by demographic or histological features are inconsistent due to a univariate analysis of limited case numbers. The aim of the present study was to determine such an association by the use of a large series of patients and multiple variables analysis. The serum IgG antibodies against H. pylori were measured in 397 patients with histologically verified gastric cancer. A multiple logistic regression analysis was used to define the association between seropositivity and demographic or tumour characteristics of gastric cancer. The overall seropositivity of H. pylori was 63%. In univariate analysis, the prevalence was significantly lower among patients with cardia (50%) or diffuse-type (56.6%) cancers than those with non-cardia (64.8%) or intestinal-type (70.3%) cancer (P < 0.05 and P < 0.01, respectively). There was no statistical difference between H. pylori infection rate and gender, age or tumour stage. A multiple logistic regression analysis showed tumour location and histology remained significant factors associated with seropositivity of H. pylori with an odds ratio of approximately 2.0. Analysis of combined histology and location revealed that patients with intestinal-type cancer at non-cardia locations had the highest odds ratio of 3.93 (95% confidence interval (CI): 1.55-10.0) compared with the lowest odds ratio of 0.69 (95% CI: 0.30-1.62) in diffuse cardia cancer (P < 0.005). Our data indicate H. pylori infection in gastric cancer is independently affected by the histological subtype and by tumour location.

The effect of 0.5% timolol maleate on the ocular perfusion of ocular hypertensive patients by scanning laser flowmetry

To understand the effect of 0.5% timolol maleate on the ocular perfusion of the optic disc and macula in ocular hypertensive patients, we enrolled 10 males and 15 females without any systemic or ocular disease, except intraocular pressure higher than 20 mmHg. Their average age was 33 +/- 13 y/o (range 14-45). Under the randomized, double-masked design, one drop of 0.5% timolol maleate was given in one eye, and placebo in the fellow eye. Heart rate, blood pressure, intraocular pressure, and ocular perfusion were measured at baseline, and then 30 minutes and 2 hours after treatment. Ocular perfusion was measured by Heidelberg Retina Flowmeter (Heidelberg Engineering GmbH, Heidelberg, Germany). We used 10 degrees measurement field and 10 x 10 pixels measurement frame. Four areas were measured, i.e., temporal upper, temporal lower, and nasal parts of the optic disc, and macula. In comparison to the baseline, the treated eyes had a slight reduction of blood flow, volume, and velocity 30 minutes after treatment, but these parameters came back close to the baseline value at 2 hours after treatment. Similar changes were also noted in the control eyes. The results showed that a single drop of 0.5% timolol had minimal effects on the retinal and macular circulation within 2 hours after treatment.

Benign recurrent intrahepatic cholestasis

Benign recurrent intrahepatic cholestasis is a rare disorder of unknown etiology and has not yet been reported in Taiwan. We report a case with a typical clinical course. A 17-year-old Taiwanese boy had three episodes of pruritus and jaundice from February 1993 to July 1995, each lasting 3 to 4 months. Jaundice spontaneously subsided and he was symptom-free during periods of remission. A fourth episode of pruritus began in July 1995, with jaundice developing later and lasting for 3 months. Laboratory tests revealed direct hyperbilirubinemia. Endoscopic retrograde cholangiopancreatography showed normal intra- and extrahepatic biliary trees. Light microscopy of a liver biopsy sample revealed hepatocellular and canalicular cholestasis with bile retention in the Kupffer cells. Benign recurrent intrahepatic cholestasis was diagnosed after exclusion of other possible causes of jaundice. The patient made an uneventful recovery.

Genetic alterations in gastric cancer: relation to histological subtypes, tumor stage, and Helicobacter pylori infection

BACKGROUND & AIMS

A different spectrum of genetic changes including p53, c-erbB-2, c-met, adenomatous polyposis coli (APC), and deleted in colorectal cancer (DCC) is involved in gastric cancer (GC). The aim of this study was to correlate these alterations with histological subtypes, tumor stages, and Helicobacter pylori infection.

METHODS

Specimens of 163 patients with GC were immunostained for p53, c-erbB-2, and c-met, and polymerase chain reaction was performed in them to determine loss of heterozygosity (LOH) of APC and DCC.

RESULTS

Overexpression of p53 was more frequent in early intestinal than early diffuse GC and was noted in the stage progression of diffuse but not intestinal GC. Overexpression of c-erbB-2 occurred more commonly in intestinal GC and advanced GC of both types. Overexpression of c-met was greater in diffuse GC, particularly at advanced stage. LOH of APC was more common in intestinal GC irrespective of the stage but rarely in diffuse GC. LOH of DCC occurred primarily in advanced intestinal GC and infrequently in early GC or advanced diffuse GC. Alterations of these five genes were not correlated with H. pylori infection.

CONCLUSIONS

A distinct genetic pathway exists in gastric carcinogenesis of different histological subtypes and their tumor progression, in which H. pylori infection may play an equal role or no role.

Chronic calcifying pancreatitis in Taiwan: a multicentric study and comparison with western countries

BACKGROUND/AIMS

This study investigates the clinical features of chronic calcifying pancreatitis (CCP) in Taiwan and also the comparative differences in the disorder as it affects orientals and occidentals.

MATERIALS AND METHODS

Medical records at seven tertiary hospitals relating to patients diagnosed with CCP between 1976 and 1996 are reviewed and analyzed. Ninety patients were enrolled. Defining the calcification of the pancreas is achieved by plain film, ultrasonography, computed tomography, or histology.

RESULTS

CCP afflicts men more frequently than it does women, by a ratio of 3.5:1 (70 men and 20 women). The mean age is 45 years (male: 46 female: 41.4). For fifty-two patients (57.8%), alcohol is the major cause of the condition, while in others, the causes are non-alcoholic (idiopathic: 31; biliary: 4; hereditary: 3). Alcoholism is mainly associated with males and younger sufferers. The major complications are diabetes mellitus (53.3%), cysts or pseudocysts (21.1%), and biliary stricture or stones (20%). Pancreatic adenocarcinoma and splenic vein thrombosis were found in six and five patients, respectively. Three patients died from cancers of other than pancreatic origin (lung: 1;liver: 1;bile duct: 1). Thirty-three patients were treated surgically of which thirteen (39.4%), including one with pancreatic auto transplantation, improved. Fifty-seven patients received medical treatment but only eleven (19.3%) improved.

CONCLUSIONS

The clinical features of CCP in Taiwan are notably similar to those manifesting in western countries and in Japan. With the changes in life style and increased alcoholic consumption in Taiwan, the prevalence of CCP may increase and its demographic features may alter in the future.

Relationship of p53 and c-erbB-2 expression to histopathological features, Helicobacter pylori infection and prognosis in gastric cancer

BACKGROUND/AIMS

Conflicting results concerning the relationships between abnormal expression of p53 and c-erbB-2 and biologic behavior of gastric cancer are noted. Therefore, overexpression of p53 and c-erbB-2 in relation to the following aspects of gastric cancer: tumor histopathology, Helicobacter pylori infection, and prognosis are explored.

MATERIALS AND METHODS

Expression of p53 and c-erbB-2 by immunohistochemistry was correlated with histopathology, H. pylori infection and prognosis of gastric cancer in 112 patients.

RESULTS

Positive p53 staining was found in 61 (54.5%) of 112 tumors examined. There was no association of p53 expression with sex, age, lymph node metastasis, H. pylori infection or prognosis. A significantly higher frequency of p53-positive staining was observed in advanced (60.7%), intestinal (69.8%) and cardia (76.5%) than in early (30.4%, p < 0.01), diffuse (34.7%, p < 0.01) and noncardia (50.5%, p < 0.05) carcinoma, respectively. Expression of c-erbB-2 was found in 34 cases (30.3%), and was not related to sex, age, H. pylori infection and tumor location. Tumors with positive c-erbB-2 staining appeared to behave more aggressively in view of higher rates of nodal metastasis (38.0% vs 17.1%, p < 0.05), advanced stage (37.1% vs 4.3%, p < 0.01) and poor mean survival (p < 0.01). Patients with intestinal type tumors also had a significantly higher rate of c-erbB-2 expression than those with diffuse tumors (39.7% vs 18.4%, p < 0.01).

CONCLUSIONS

Our results indicate that immunohistochemical expressions of p53 and c-erbB-2 are significantly associated with some histopathological phenotypes. Genetic alterations of c-erbB-2 or p53 may not be affected by H. pylori infection. C-erbB-2 expression may be used as a marker for identifying more aggressive gastric cancer for designing further therapy.

Infrequent hMSH2 mutations in sporadic gastric adenocarcinoma with microsatellite instability

The status of genetic instability was determined with seven microsatellite markers from 40 patients with primary gastric adenocarcinoma. For those cases with microsatellite instability, alterations of hMSH2 were further investigated by direct sequencing of reverse transcription-polymerase chain reaction products. Twelve (30%) of 40 patients were found to have microsatellite instability. Among them, one patient (1/6, 16.7%) was early gastric cancer and 11 (11/34, 32.4%) were advanced gastric cancer. There were seven patients with diffuse type (7/18, 38.7%), while five (5/22, 22.7%) were intestinal type tumors. The entire coding region of the hMSH2 gene in these 12 affected individuals was amplified and sequenced. Only a 41-year-old female patient with diffuse type advanced gastric cancer showed a GCT to TCT missense mutation at codon 207 with predicted protein change from alanine to serine. Our results indicate that genetic instability plays an important role in gastric tumorigenesis and alterations of the hMSH2 gene are related to only a small portion of sporadic gastric adenocarcinoma with microsatellite instability.

Superinfection by homotypic virus in hepatitis C virus carriers: studies on patients with post-transfusion hepatitis

Although heterotypic superinfection and mixed infections of hepatitis C virus (HCV) may be possible for hepatitis flares in chronic hepatitis C, the possibility of homotypic HCV superinfection in HCV carriers with post-transfusion hepatitis has not been explored. Six HCV carriers with post-transfusion non-A, non-B hepatitis found in a prospective study of post-transfusion hepatitis were included. Serum samples before transfusion and during hepatitis were selected to determine genotypes of HCV and nucleotide sequences of the hypervariable region (HVR). The genotypes identified before and after transfusion were concordant in all. There were four with type 1b and one each with type 2a and type 2b. Amplified nucleotide sequences of the HVR before transfusion and during hepatitis were compared in four patients, and a > 95% homology was observed in three, suggesting persistence of original viruses. In contrast, only a 51% homogeneity was seen in a given patient, suggesting a homotypic HCV superinfection. Phylogenetic tree analysis validated further these findings. This study implies that HCV carriers can be reinfected by homotypic HCV, and this may contribute to hepatitis flares in chronic hepatitis C. These findings also confirm a weak or inadequate protective immunity in HCV infection and justify protection from reinfection of HCV of patients with chronic hepatitis C.

Incomplete pancreas divisum coexistent with anomalous union of pancreaticobiliary duct--report of a Chinese patient

The coexistence of incomplete pancreas divisum and anomalous union of pancreaticobiliary duct is uncommon and, to the best of our knowledge, has been reported only in three patients who also presented with choledochal cysts. We have encountered a 54-year-old patient with symptom of intermittent right upper quadrant pain. Endoscopic retrograde cholangiopancreatography revealed coexistence of incomplete pancreas divisum and anomalous union of pancreaticobiliary duct, but no dilatation of bile duct.

Effective reduction of Helicobacter pylori infection after upper gastrointestinal endoscopy by mechanical washing of the endoscope

BACKGROUND/AIMS

To investigate the frequency of endoscopic transmission of Helicobacter pylori and the efficiency of disinfection in different washing methods of endoscopes.

MATERIALS AND METHODS

IgG antibodies to H. pylori in patients prospectively followed who underwent first endoscopic examination at the National Taiwan University Hospital from 1982 to 1993 were measured. A total of 132 subjects who were negative for H. pylori IgG antibody test before examination and who were with negative endoscopic findings were enrolled. Among the 132 seronegative patients, 60 were examined before June 1989 when manual washing was adopted for endoscope cleaning and 72 received examination after mechanical washing were routinely used in our endoscopy unit.

RESULTS

During a follow-up period of 6 months or more, 5 patients in the manual washing group sero-converted while none in the mechanical washing group seroconverted (5/60 vs 0/72. p = 0.02).

CONCLUSION

The results suggested that the risk of endoscopic transmission of H. pylori is substantial and mechanical washing is efficient in preventing this iatrogenic spread.

Interleukin-3 increases the incidence of 5-azacytidine-induced thymic lymphomas in pBOR-Il-3 mice

Interleukin-3 (Il-3) is a glycoprotein produced by a CD4+CD8- subpopulation of T-lymphocytes. Il-3 has been associated with the proliferation of bone marrow stem cells and their differentiation to granulocytes, macrophages, basophil/mast cells, megakaryocytes, erythroid cells, and neutrophils. The pBOR-Il-3 transgenic mice were developed by pronuclear microinjection to study how chemical insults modulate transcription of the Il-3 gene driven by a long-terminal repeat (LTR) of an endogenous retrovirus and to determine the biological consequences of interleukin-3 expression. We injected 5-azacytidine, a demethylating agent, to increase the LTR-driven expression of Il-3. Upon 5-azacytidine treatment, both the pBOR-Il-3 and the FVB/N nontransgenic controls developed thymic lymphomas. The pBOR-Il-3 mice developed thymic lymphomas at a higher frequency than the FVB/N mice. The thymic lymphoma cells were of a T-cell origin, as determined by T-cell receptor gene rearrangement analysis, and, in most cases, were of monoclonal origin. According to flow cytometric analysis of CD3, CD4, and CD8 cell surface markers, the thymic lymphoma cells did not lose their ability to differentiate, but the differentiation process was aberrant. Flow cytometric analyses also revealed that in pBOR-Il-3 mice the thymic lymphomas are mostly of a CD8+CD4- origin, whereas in the FVB/N group, the predominant type of thymic lymphoma is of a CD4+CD8- origin.

Transmission of hepatitis C virus between spouses: the important role of exposure duration

OBJECTIVES

Although interspousal transmission of hepatitis C virus (HCV) has been studied, the factors responsible for it remain unclear.

METHODS

To investigate the transmission of HCV between spouses and the related risk factors, 100 anti-HCV-positive index patients and their spouses were studied.

RESULTS

Overall, anti-HCV was detected in 17 (17%) spouses, 15 of whom were also positive for HCV RNA, and 11 couples were infected with the same genotype. The anti-HCV-positive rate was higher in spouses married longer than 20 yr compared with those married less than 20 yr (22 vs 6%, p < 0.05), and the infection was correlated with the duration of their actual exposure to the index patients but not with serum HCV titers. The infected couples had more frequent sexual contacts and more commonly shared tooth-brushes than those with uninfected spouses.

CONCLUSION

Spouses of patients with chronic hepatitis C have a higher risk of acquiring HCV that increases with longer marriage and duration of exposure, and they should be educated about how to avoid contracting HCV infection from their spouses.

Intragenic homozygous deletions of MTS1 gene in gastric cancer in Taiwan

The multiple tumor suppressor 1 (MTS1) and 2 (MTS2) genes, located on chromosome 9p21, have been reported to be deleted or mutated in many malignant cell lines and in a high percentage of some primary carcinomas. To determine whether these genes are altered, and if so, what is the nature of the alterations, in human gastric adenocarcinoma, we investigated their frequency of mutation by Southern blotting, polymerase chain reaction (PCR) and direct sequencing in 55 patients. Furthermore, loss of heterozygosity (LOH) of chromosome 9p21 at the IFNA locus and D9S171 was assessed. Homozygous deletions of exon 1 of the MTS1 gene were identified in 5 of 55 (9.1%) primary tumors. No deletion of MTS2 gene was noted. LOH was observed in 7 (14.3%) of 49 informative cases (5 cases at IFNA locus, 2 cases at D9S171 and one case with combined LOH at D9S171 and homozygous deletion at exon 1 of MTS1). Direct sequencing of PCR products of the MTS1 and MTS2 gene did not reveal any point mutation in these 55 patients. These data indicate that alterations of the MTS1 and MTS2 genes are infrequently encountered. Additional studies of LOH with more microsatellite markers near 9p21 are mandatory to elucidate whether another tumor suppressor gene exists in the vicinity of MTS1 in primary gastric adenocarcinoma.

A prospective study of transfusion-transmitted GB virus C infection: similar frequency but different clinical presentation compared with hepatitis C virus

To study the incidence and outcome of GB virus C (GBV-C) infection in blood recipients. Serum samples collected in a prospective study were examined for GBV-C RNA by a nested polymerase chain reaction assay. Among the 400 adults who underwent cardiac surgery, 40 were positive for GBV-C RNA, including six whose pretransfusion sera were already positive and seven coinfected with hepatitis C virus (HCV) during transfusion. The risk of transmission was estimated to be approximately 0.46% per donor. GBV-C viremia was detectable 1 week after transfusion and could persist for 8 years. However, no evident symptoms or signs were noted in the 25 patients infected by GBV-C alone, and the average peak serum alanine aminotransferase activity was 31 IU/L only (range, 12 to 123), with persistently normal levels in 20 patients. In the seven patients coinfected with HCV, the clinical courses of posttransfusion hepatitis were similar to those infected by HCV alone. In eight patients with posttransfusion non-A approximately E hepatitis, only one was positive for GBV-C RNA. Sixty samples were chosen to test hepatitis G virus (HGV) sequences, 26 of the 30 GBV-C positives were positive for HGV RNA in contrast to none of the 30 GBV-C negative samples. In conclusion, GBV-C can be transmitted by transfusion in approximately 9% of patients who underwent cardiac surgery. Nevertheless, this virus does not seem to cause classic hepatitis in most instances.

Ultrasound-guided cutting biopsy for the diagnosis of hepatocellular carcinoma--a study based on 420 patients

BACKGROUND/AIMS

To evaluate ultrasound-guided cutting biopsy for hepatocellular carcinoma, we report findings from 10 years of experience.

METHODS

We performed 455 ultrasound-guided cutting biopsies of hepatic tumors in 420 patients with hepatocellular carcinoma from 1981 to 1990.

RESULTS

Liver tissues were adequately sampled for a histological diagnosis of hepatocellular carcinoma in the initial biopsy in 391 sessions. The remaining 64 were proved to have hepatocellular carcinoma after subsequent studies. Ultrasound-guided biopsy changed the initial diagnosis in 9 of the 420 patients: three had been diagnosed with liver abscess, and six with metastatic liver tumors. Complications of the biopsy were rare: the tumor had spread to the chest wall in nine, and internal bleeding was noted in five patients. There was no mortality and no other sequelae.

CONCLUSIONS

Ultrasound-guided biopsy of hepatic tumors is important in the diagnosis of liver cancer, but this technique should be applied only when the image diagnosis and results of fine needle biopsy are equivocal to minimize possible complications. For patients with small HCCs, who are candidates for surgical resection of hepatocellular carcinoma or liver transplantation, it should not be considered as a first-step invasive procedure.

Organization of the Haemophilus ducreyi 35000 chromosome

A physical and rudimentary genetic map of the Haemophilus ducreyi strain 35000 genome was constructed. Pulsed-field gel electrophoresis was used to separate restriction fragments of H. ducreyi DNA digested with Sfil, I-Ceul, or Sfil plus I-Ceul. The sizes of the fragments were determined, and the circular chromosome was estimated to be 1757 kbp. The six I-Ceul fragments and four Sfil fragments were ordered into macrorestriction maps using Southern blot hybridization with random H. ducreyi clones as probes. It was shown that both H. ducreyi and the distantly related Haemophilus influenzae have six rrn operons marked by the locations of the I-Ceul sites. However, the two species displayed distinct I-Ceul restriction patterns. A second H. ducreyi strain, CIP542, displayed an identical I-Ceul pattern to that of H. ducreyi 35000, but Sfil digests of teh two strains were distinct. The orientation of the six rrn operons was determined and thirteen identified H. ducreyi genes positioned on the map of strain 35000.

Helicobacter pylori in tumor tissues of patients with advanced gastric adenocarcinoma: high prevalence but failure to detect integration

Helicobacter pylori has been known to be associated with gastric adenocarcinoma by case control studies. However, significant portion of patients with gastric carcinoma are negative for H. pylori by serological test. To further detect the presence of H. pylori infection in serum and tissue of patients with gastric adenocarcinoma, paired tissues and serum samples from 32 patients with gastric adenocarcinoma were tested. Antibodies to H. pylori were tested by an enzyme linked immunosorbent assay (ELISA) and a Western blot analysis. H. pylori in tumor and non-tumor parts of gastric tissues were examined by histology and polymerase chain reaction (PCR). For serum antibody, eighteen (56%) of these patients were positive by ELISA while 24 (75%) were positive by Western blot. For tissue H. pylori genome, 14 were positive by histology while 28 (87%) were positive by PCR. Southern blot analysis of both tumor and non-tumor tissues revealed no evidence of integration of H. pylori DNA in the human genomes. These results suggest that H. pylori infection can be detected in most patients with gastric adenocarcinoma, and PCR and Western blot can further identify seronegative patients.

p53, apoptosis and human cancers

More than half of human cancers contain p53 mutations. Structural analyses of p53-DNA interactions indicate that hot spots of p53 mutation are often either involved in direct contact with target DNA or those that maintain specific conformation of p53. One significant consequence of the loss of wild type p53 function is inhibition of apoptosis, which may be through the inability of mutant p53 to transcriptionally activate bax gene expression. Quantitative correlation among ultraviolet-induced p53 mutations of keratocytes, inhibition of apoptosis and the development of squamous cell cancer of the skin further suggest a central role of inhibited apoptosis between p53 mutations and tumorigenesis. Hypoxia-mediated selection for p53 mutant cells with diminished apoptotic potential in solid tumors may account for the high prevalence of p53 mutations in human cancers. Our increasing understanding of the role of p53 mutations and apoptosis in human cancers has also provided some insights into strategies for anticancer therapy. Studies reconstituting the wild-type p53 through gene therapy have been encouraging. More importantly, further elucidation of the mechanisms of therapy-induced p53-independent apoptosis in cancer cells will facilitate the development of more efficient, less toxic anticancer therapy.

Absence of extensive genetic heterogeneity of hepatitis C virus in antibody-negative chronic hepatitis C

Hepatitis C virus (HCV) carriers usually have antibodies to HCV; however, there are viremic individuals without these antibodies. To investigate whether variations of the viral genome are responsible for this discrepancy, the nucleotide and deduced amino acid sequences of HCV capsid and nonstructural regions obtained from 15 viremic patients were examined. These 15 patients were infected with type 1b HCV, and 10 did not have antibody to HCV assayed with second-generation tests. The nucleotide homology of the 5 seropositive and 10 seronegative patients with the HCV prototype sequence were 91.6% and 91.9%, respectively, in the capsid region. There was no apparent difference in the deduced amino acid sequences between the two groups of patients studied (94% vs. 95%). The nucleotide and amino acid sequences of a part of the nonstructural region 3 also showed similar results. These findings suggest that absence of antibodies against both capsid and nonstructural peptides in HCV carriers is not caused by genetic heterogeneity of the viral epitopes.

Topical ointment therapy benefits premature infants

OBJECTIVE

Premature infants have an ineffective epidermal barrier. The aim of this study was to investigate the cutaneous and systemic effects of preservative-free topical ointment therapy in premature infants.

STUDY DESIGN

We conducted a prospective, randomized study of 60 infants less than 33 weeks' estimated gestational age. The treated infants received therapy for 2 weeks with twice-daily preservative-free topical ointment therapy while the control group received no topical treatment or as-needed therapy with a water-in-oil emollient. Data collection included transepidermal water loss (TEWL) measurement, skin condition evaluations, fungal and quantitative bacterial skin cultures, analysis of fluid requirements, patterns of weight low or gain, and the incidence of blood and cerebrospinal fluid cultures positive for microorganisms.

RESULTS

We found that topical ointment therapy significantly decreased TEWL during the first 6 hours after the initial application. TEWL was decreased by 67% (p = 0.0001) when measured 30 minutes after application and 34% (p = 0.001) when measured 4 to 6 hours after application. We also observed significantly superior skin condition scores in the treated group on study days 7 and 14 (p = 0.001) and 0.0004, respectively). Quantitative bacterial cultures revealed significantly less colonization of the axilla on day 2, 3, or 4 and on day 14 (p = 0.008 and 0.04, respectively). The incidence of positive findings in blood and/or cerebrospinal fluid cultures was 3.3% in the treated group of infants versus 26.7% in the control group (p = 0.02). There was no statistical difference in the fluid requirements or patterns of weight gain or loss during the 2 weeks of the study.

CONCLUSIONS

Preservative-free topical ointment therapy decreased TEWL for 6 hours after application, decreased the severity of dermatitis, and decreased bacterial colonization of axillary skin. Infants treated with ointment had fewer blood and cerebrospinal fluid cultures positive for microorganisms. These data support the use of topical ointment therapy in very premature infants during the first weeks after birth.

Screening techniques for angle-closure glaucoma in rural Taiwan

562 residents of Jin Shan aged 40 years and above underwent examinations to compare the sensitivity and specificity of oblique flashlight, peripheral slit beam and ultrasonographic evaluation of the anterior chamber depth to gonioscopy in detecting cases of PACG. Among 5441 eligible individuals aged 40 and above, 562 (10.3%) underwent screening for PACG, of whom 17 (3.02%) were defined as cases, and 10 (1.78%) as suspects. Home visits indicated that respondents for screening were similar to the population as a whole. Only 35% of PACG cases reported symptoms consistent with acute angle closure, and only 18% were previously diagnosed. When compared to gonioscopy, only ultrasonographic measurement of AC depth provided an adequate mix of sensitivity and specificity. Ultrasonography in combination with tonometry provided a sensitivity of 88% with a specificity of 92%. Sensitivity and specificity for ultrasonography in combination with refractive status were 84% and 83% respectively. Shallower AC depth (p = 0.0001), shorter axial globe length (p = 0.001), greater than 2D of hyperopia (p < 0.001), high grades of nuclear sclerotic cataract (p < 0.0001) and an increased cup-to-disc ratio (p = 0.002) were significantly correlated with a diagnosis of PACG.

Serotyping of hepatitis C virus in chronic type C hepatitis in Taiwan: correlation with genotypes

To evaluate the usefulness of a new serologic assay to group hepatitis C virus (HCV), genotypes identified by this serotyping method were compared to those identified by a polymerase chain reaction (PCR) assay with type-specific primers in 71 Taiwanese patients with chronic type C hepatitis. The group-specific antibodies against different HCV genotypes were detected by using an enzyme-linked immunosorbent assay (ELISA) based on group-specific recombinant peptides (C14-1 and C14-2) within the NS4 region. Among 71 patients positive for current second-generation HCV antibodies, HCV RNA was detected in 55 patients by PCR with primers from the 5' untranslating region, and in 52 by genotype-specific PCR. In 49 (89%) of 55 viremic patients, the results of serotyping by ELISA showed complete agreement with those determined by PCR genotyping, and none of the patients showed a group opposite to that of HCV genotype. The positive rate of group-specific antibodies (69/71;97%) was even better than that of the PCR (55/71;78%). We conclude that this new serotyping assay is highly sensitive and specific for the determination of HCV genotypes, and will be useful in future epidemiologic studies, as well for clinical application.

Hemosuccus pancreaticus from a splenic artery pseudoaneurysm: an unusual cause of upper gastrointestinal bleeding

Hemorrhage through the pancreatic duct into the duodenum, so called "hemosuccus pancreaticus", is a rare cause of gastrointestinal bleeding with diagnostic difficulties. We report a 60-year-old man with recurrent upper gastrointestinal bleeding due to rupture of a splenic artery pseudoaneurysm into the pancreatic duct. Initial upper gastrointestinal endoscopy failed to identify the site of the hemorrhage. Abdominal computed tomography disclosed a cystic mass containing a well-enhanced spherical area at the pancreatic tail. Arterial blood flow was demonstrated in the lesion by Doppler ultrasound. Celiac angiography demonstrated a saccular pseudoaneurysm arising from the splenic artery. Bleeding from the ampulla of Vater located in a big duodenal diverticulum was found on repeat endoscopy. Surgical resection of the pseudoaneurysm with distal pancreatectomy and splenectomy was successfully performed. The patient remained symptom-free 5 months after the operation. Hemosuccus pancreaticus, although rare, remains important in the differential diagnosis of upper gastrointestinal bleeding of obscure origin.

Exfoliation syndrome

Increasing pathophysiologic evidence indicates that exfoliation syndrome, a systemic process involving various visceral organs, frequently manifests itself first in the eyes as exfoliation of the lens and glaucoma. Exfoliation syndrome occurs when several tissues synthesize an abnormal basement membrane protein. This protein may obstruct the trabecular meshwork in the eye and cause glaucoma. We present a case of exfoliation syndrome associated with angle-closure glaucoma in a 57-year-old male patient from Taiwan. After peripheral iridectomy and topical antiglaucoma medications, intraocular pressure in both eyes was well controlled in the range of 15 to 20 mmHg. The mechanism of the glaucomatous optic neuropathy in this patient was probably caused by chronic angle-closure glaucoma superimposed with the exfoliation syndrome.

Chronic hepatitis C without anti-hepatitis C antibodies by second-generation assay. A clinicopathologic study and demonstration of the usefulness of a third-generation assay

To study the clinicopathologic features of hepatitis C viremic patients negative for hepatitis C antibodies (anti-HCV) by current second-generation assay, we categorized 139 consecutive histologically verified patients with chronic non-A, non-B hepatitis into three groups: 121 (87%) were positive for second-generation anti-HCV (group A); 10 (7%) were negative for second-generation anti-HCV but positive for HCV RNA (group B); and 8 (6%) were negative for both antibodies and viremia (group C). Six (60%) of group B patients could be, further detected by a new third-generation assay, but none of group C patients was third-generation anti-HCV-positive. The demographic features, mean peak serum alanine aminotransferase levels, HCV genotype distribution, and histologic changes were comparable among the three groups. The study indicates that most patients with chronic hepatitis C in Taiwan could be identified by current second-generation assay, and viremic but antibody seronegative patients were clinicopathologically similar to the seropositives. Most patients of the latter group could be diagnosed by a third-generation assay, indicating the usefulness of this assay.

A novel tree-structured analysis for non-invasive diagnosis of gastric adenocarcinoma

Non-invasive diagnosis of gastric adenocarcinoma (GAC) is usually difficult due to the low sensitivity and specificity of serologic markers,including pepsinogens and gastrin. For the improvement of the diagnostic values of these markers, a "recursive partitioning and amalgamation" algorithm was employed to construct a decision protocol. A total of 636 subjects including 161 healthy subjects, 163 patients with GAC, 196 with gastric ulcer and 116 with duodenal ulcer were enrolled. Serum levels of gastrin, pepsinogen I, pepsinogen II, and the ratio of pepsinogen I / pepsinogen II were determined for each of the subjects. The proposed "decision tree" classifies subjects into five subgroups with different risks of GAC and peptic ulcer, based on the information of age, serum pepsinogen and gastrin levels. Using this novel analysis system, an expected probability of GAC or ulcers could be obtained. Patients with an age > 62 years and a serum level of pepsinogen I < or = 33 ng/ml were strongly indicated for further confirmatory tests of GAC. This treestructured analysis is also helpful in clarifying the interactions between various serologic markers and demographic factors.

Genotypes of hepatitis C virus in Taiwan and the progression of liver disease

The existence of four genotypes of hepatitis C virus (HCV)--types 1a, 1b, 2a, and 2b--has been suggested based on variations in nucleotide sequences of the core region. The aim of this study was to investigate the prevalence of HCV genotypes in chronic type C liver disease in Taiwan and correlate distinct genotypes to severity of liver disease. The genotypes of 175 patients with chronic type C liver disease were determined by a polymerase chain reaction with type-specific primers. The prevalence of each genotype in Taiwan was as follows: type 1a, n = 1 (0.6%); 1b, n = 125 (71.4%); 2a, n = 21 (12%); 2b, n = 6 (3.4%); mixed types, n = 18 (10.3%); and unclassified, n = 4 (2.3%). The demographic and clinical features were comparable between patients with different genotypes, except that the mean peak serum transaminase levels of patients with double viruses and type 1b HCV infections were significantly higher than were those of patients with type 2a virus. Moreover, type 1b HCV was more prevalent in patients with liver cirrhosis alone or with hepatocellular carcinoma. In conclusion, type 1b virus is the predominant genotype in chronic hepatitis C in Taiwan, and type 1b virus and mixed infection may trigger more severe liver disease.

Microsatellite instability in gastric carcinoma with special references to histopathology and cancer stages

To study the molecular mechanism of gastric carcinogenesis, the frequencies of microsatellite instability were evaluated with seven dinucleotide repeat loci in 59 patients with gastric carcinoma. Microsatellite instability at two or more loci was found in 41.5% (17/41) of advanced gastric carcinoma, 21.4% (3/14) of early gastric carcinoma, but not in remnant gastric carcinoma (0/4), with an overall frequency of 33.9% (20/59). Diffuse gastric carcinoma had a similar prevalence (32.1%, 9/28) to intestinal gastric carcinoma (40.7%, 11/27). The frequency of microsatellite instability in gastric carcinoma was not significantly different with respect to age, sex and Helicobacter pylori infection. Microsatellite instability tended to occur more frequently in cancers of the cardia (62.5%, 5/8) compared with cancers of other stomach regions (31.9%, 15/47), but the difference was not statistically significant. These data suggest that microsatellite instability occurs in early gastric carcinoma and its occurrence increases during tumour progression. Furthermore, its frequency was independent of age, gender, histological types and Helicobacter pylori infection.

Impact of age, various forms of cataract, and visual acuity on whole-field scotopic sensitivity screening for glaucoma in rural Taiwan

OBJECTIVE

To evaluate the impact of age, various forms of cataract, and visual acuity on whole-field scotopic sensitivity screening for glaucoma in a rural population.

DESIGN

Clinic-based study with population-based recruitment.

SETTING

Jin Shan Township near Taipei, Taiwan.

SUBJECTS

Three hundred forty-six residents (ages, > or = 40 years) of Jin Shan Township.

INTERVENTIONS

Whole-field scotopic testing, ophthalmoscopy with dilation of the pupils, cataract grading against photographic standards, and screening visual field testing in a random one-third subsample.

MAIN OUTCOME MEASURES

Whole-field scotopic sensitivity (in decibels) and diagnostic status as a case of glaucoma, glaucoma suspect, or normal.

RESULTS

Participants in Jin Shan Township did not differ significantly in the rate of blindness, low visual acuity, or family history of glaucoma from a random sample of nonrespondents. Scotopic sensitivity testing detected 100% (6/6) of subjects with open-angle glaucoma at a specificity of 80.2%. The mean +/- SE scotopic sensitivity for six subjects with open-angle glaucoma (32.78 +/- 1.51 dB) differed significantly from that of 315 normal individuals (38.51 +/- 0.22 dB), when adjusted for age and visual acuity (P = .05, t test). With linear regression modeling, factors that correlated significantly with scotopic sensitivity were intraocular pressure, screening visual field, best corrected visual acuity, presence of cortical cataract, and increasing age.

CONCLUSIONS

Although cataract affects the whole-field scotopic threshold, it appears that scotopic testing may be of value in field-based screening for glaucoma.

Gestational trophoblastic diseases: current trends and perspectives

Gestational trophoblastic diseases (GTD) include a spectrum of diseases from the potentially premalignant hydatidiform mole to the highly aggressive choriocarcinoma. Most complete moles have diploid chromosomes, nearly always of pure paternal origin, whereas most partial moles have triploid chromosomes, containing one haploid maternal set and two paternal sets. The first-line treatment of molar pregnancies is suction evacuation. In patients with persistent trophoblastic diseases or choriocarcinoma, single agent or multiagent chemotherapy is indicated, depending on the prognostic score of the individual patient. With careful follow-up and appropriate treatment, nearly all patients with gestational trophoblastic diseases can be cured. Although many advances have been made in the cytogenetics, molecular biology and immunobiology of GTD, the reasons for its unique curability remain unclear. Studies comparing induction of apoptosis and multidrug resistance gene expression, in normal trophoblasts and GTD, may elucidate the mechanism behind the good response of GTD to chemotherapy. This may give some innovative insight into chemoresistance.

Effect of hepatitis C antibody screening in blood donors on post-transfusion hepatitis in Taiwan

A national screening programme for antibody to hepatitis C virus (HCV) in blood donors in Taiwan began in July 1992 using a second-generation immunoassay. To study the impact of this screening on post-transfusion hepatitis in Taiwan, a prospective study on post-transfusion hepatitis, that was started in 1987, was continued. As of June 1994, 245 patients who received a blood transfusion after July 1992 had completed a follow-up period for more than 6 months post-transfusion. Of them, seven (2.8%) recipients developed acute post-transfusion hepatitis. The hepatitis in six cases could not be attributed to infection by hepatitis A, B, C, D, E viruses or cytomegalovirus (CMV) or Epstein-Barr virus (EBV). The remaining patient seroconverted to both IgG and IgM anti-CMV. All seven patients recovered in 6 months without development of chronicity, and the mean peak alanine aminotransferase level was lower compared with that of the cases before anti-HCV screening (i.e. pre-July 1992). These results indicate that the current anti-HCV screening has effectively interrupted HCV transmission through blood transfusion in Taiwan.

Serum pepsinogen I and pepsinogen II, and the ratio of pepsinogen I/pepsinogen II in peptic ulcer diseases: with special emphasis on the influence of the location of the ulcer crater

To investigate the effect of the location of the ulcer crater on the serum levels of pepsinogen I (PGI), pepsinogen II (PGII) and the ratio of PGI/PGII, these parameters were determined in 161 healthy controls, 29 patients with gastric ulcer in the gastric body (GU-I), 65 with coexistent gastroduodenal ulcer (GU-II), 104 with gastric ulcer in the prepyloric region (GU-III), and 116 with duodenal ulcer (DU). Serum PGI levels were significantly higher (P < 0.01) in patients with GU-III (110.6 +/- 65.1 ng/mL), GU-II (100.0 +/- 46.6 ng/mL), and DU (92.2 +/- 35.2 ng/mL) than in the controls (77.4 +/- 31.4 ng/mL), while there were no significant differences between GU-I (82.5 +/- 36.3 ng/mL) and the controls. Patients with gastric ulcer in any region had significantly higher (P < 0.01) serum PGII levels (GU-I, 20.0 +/- 15.7 ng/mL; GU-II, 15.5 +/- 10.9 ng/mL; GU-III, 14.3 +/- 10.0 ng/mL) than the controls (10.6 +/- 6.0 ng/mL) and the patients with DU (10.0 +/- 5.5 ng/mL), whereas no significant differences existed between the latter two. The ratio of PGI/PGII in GU-I (5.86 +/- 3.90) was significantly lower (P < 0.01) than any other group (controls, 8.83 +/- 4.70; GU-II, 8.33 +/- 4.99; GU-III; 9.64 +/- 6.13; DU, 10.45 +/- 4.49), while patients with DU it was significantly higher (P < 0.01) than any other groups. These findings indicate that peptic ulcer is comprised of a heterogeneous group of diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Quasispecies of hepatitis C virus and genetic drift of the hypervariable region in chronic type C hepatitis

The sequential variations of amino acid sequences in the hypervariable region (HVR)-1 of hepatitis C virus (HCV) and changes of viremia in 2 patients with different clinicopathologic courses of chronic hepatitis C were studied. By using polymerase chain reaction amplification, cloning, and sequencing of HVR-1, genetic heterogeneity of HCV was shown. The highest annual rate of consensus amino acid variation per 100 sites in HVR-1 of a patient with acute exacerbation was 15.4 versus 2.3 in a patient without acute exacerbation. The serial serum HCV titers were also quantified. An abrupt elevation of serum titer was associated with acute exacerbation, whereas constant viremia was observed when acute exacerbation did not occur. These results show that a quasispecies of HCV exists and patients with different courses of chronic hepatitis may have different sequential changes in virus titer and genetic drift of HVR-1.

Three-dimensional reconstruction of the biliary tract from two-dimensional biliary images

To make conventional two-dimensional cholangiography easier and more precise to read, we used techniques in computer vision to reconstruct the images in three dimensions. A 72-year-old man and a 70-year-old woman suffering from acute cholangitis were treated using endoscopic nasobiliary drainage. Their cholangiograms, from two orthogonal views, were used for three-dimensional reconstruction. We used video image-grabber and film scanner methods to digitize the original conventional biliary radiographs, and applied two different image processing methods to show the biliary structure. Both methods of three-dimensional reconstruction of the biliary tract were highly useful in evaluating the biliary tracts in these two patients, especially when a semitranslucence overlapping display technique was applied in the second patient. With this technique, the biliary tree itself and the stones inside the common bile duct can be clearly delineated. The technique of three-dimensional reconstruction of biliary images can make the conventional cholangiographs more lifelike and has great potential in surgical simulation in the near future.

Quantitative detection of hepatitis B virus DNA in human sera by branched-DNA signal amplification

Serum samples from 116 patients with hepatitis B surface antigen (HBsAg), from 7 patients without detectable HBsAg and from 71 healthy blood donors were tested by a branched DNA signal amplification (bDNA) method. Hepatitis B virus (HBV) DNA was detected in 39 (34%) of the 116 samples with HBsAg, including 19 (70%) of the 27 patients who were also positive for hepatitis B e antigen (HBeAg). In contrast, one of the 7 patients without HBsAg and none of the 71 blood donors were positive for HBV DNA. The titers of serum HBV DNA did not correlate with the serum alanine aminotransferase levels. All the samples positive by the bDNA assay were positive by the polymerase chain reaction (PCR). However, 59% of the PCR-positive samples were bDNA-negative. None of the PCR-negative samples was positive by the bDNA method. Although the sensitivity of bDNA method is not entirely satisfactory, it showed excellent specificity and reproducibility. Thus it may be considered as an alternative for quantitative detection of HBV DNA in serum samples of patients with relatively high titers of HBV viremia.

Diagnosis of gastric adenocarcinoma using a scoring system: combined assay of serological markers of Helicobacter pylori infection, pepsinogen I and gastrin

This study was carried out to develop a scoring system for the diagnosis of gastric adenocarcinoma (GAC). A total of 686 subjects, 150 patients with GAC, 182 with gastric ulcer, 127 with duodenal ulcer, and 227 subjects with negative findings, were enrolled. Analysis of the likelihood ratio (LR) showed that patients with advanced age, ulcer in the stomach, low serum levels of pepsinogen I (PGI), low PGI x gastrin values, and low PGI/gastrin ratio were likely to have GAC. Of these indicators, the serum PGI level had the greatest weight, with a LR of 7.59 for the group with a level < 30 ng/ml. A scoring system combining serum PGI level, Helicobacter pylori seropositivity, and gastric ulcer status was derived, using a logistic regression model. This scoring system was found to be better than any one-parameter criterion for diagnosing GAC after evaluation by the area under the receiver operating characteristic curve (0.84; 95% confidence interval, 0.81-0.88) or by specificity-fixed sensitivity (sensitivity 0.82 at specificity 0.72, sensitivity 0.87 at specificity 0.66, sensitivity 0.96 at specificity 0.44). This scoring system may be potentially useful as a new model for the noninvasive diagnosis of GAC in the future.

Occurrence of microsatellite instability in gastric carcinoma is associated with enhanced expression of erbB-2 oncoprotein

To investigate the molecular mechanism of gastric carcinogenesis, we examined simultaneously the frequency of microsatellite instability and the immunoreactivities to ras, erbB-2, and p53 in 42 gastric adenocarcinoma tissues. Microsatellite instability, measured by DNA replication error, was detected in 33.3% (14/42) of patients with gastric carcinoma while positive immunostaining was demonstrated in 3.1% (1/32) for ras, 40.5% (17/42) for erbB-2, and 28.6% (12/42) for p53. There was no statistical difference between the intestinal type and the diffuse type of carcinoma with respect to microsatellite instability, ras, or erbB-2 expression. The expression of p53 occurred more frequently in the intestinal type of carcinoma (41.7%, 10/24) than in the diffuse type of carcinoma (11.1%, 2/18; P < 0.01). There was no association between microsatellite instability and ras or p53 expression, while enhanced expression of erbB-2 occurred more frequently in carcinomas with microsatellite instability (64.3%, 9/14) than in those without microsatellite instability (28.6%, 8/28; P < 0.05). Such a strong association between microsatellite instability and erbB-2 oncogene may be responsible for the increase of other oncogenic mutations and tumor progression in gastric carcinogenesis.

A nested case-control study on the association between Helicobacter pylori infection and gastric cancer risk in a cohort of 9775 men in Taiwan

A nested case-control study was carried out to investigate the association between Helicobacter pylori infection and gastric cancer risk in Taiwan. A total of 29 patients newly affected with gastric cancer and 220 healthy controls matched with cases on age, sex and residence were selected from a cohort of 9,775 men recruited from 1984 through 1986. Frozen serum samples collected at recruitment examination were tested for IgG antibodies against Helicobacter pylori by an enzyme-linked immunosorbent assay. The average interval between serum collection and cancer diagnosis was 3.1 years. Gastric cancer cases had a higher seropositive prevalence (69%) than matched controls (59%) giving an odds ratio of 1.6 (95%) confidence interval = 0.7-2.6). Compared with previous nested case-control studies, Helicobacter pylori infection in early childhood may be a risk factor for gastric cancer. However, a long induction period seems required for gastro-carcinogenesis associated with Helicobacter pylori infection.