Impact of the Texas-Wide Premedical Mentoring Program during the COVID-19 pandemic

The COVID-19 pandemic disrupted the usual processes and support systems related to applying to medical school in the United States. The Texas-Wide Premedical Mentoring Program (TPMP) was established to pair medical student mentors in Texas with medical school applicants attending Texas colleges and universities. Our objective was to demonstrate the effect of the TPMP on application preparedness and self-reported mental health outcomes of program participants. A survey was developed to understand the program's impact on both mentees and mentors. Participants were sent a survey link 3 months after the TPMP launch. In total, 313 participants, comprising 62% premedical student mentees and 38% medical student mentors, completed the survey. Mentees reported a significantly positive effect of the program on anxiety, uncertainty of acceptance, connection to medicine, and making the road to medical school seem less impossible. After participation, mentees felt less alone and reported a positive impact on their perception of the application process. The TPMP positively impacted the mental wellness of both mentees and mentors, and about 80% of mentors felt more fulfilled despite not participating in clinical duties in light of suspensions. In conclusion, program participation was associated with decreasing application knowledge gaps, easing anxiety, and providing alliance for mentees. The TPMP had a similarly positive influence on the mental wellness of mentees and mentors as well as contributed to medical student mentors' sense of fulfillment.

Gut microbiome in adolescent depression

OBJECTIVES

To examine the association of major depressive disorder (MDD) and selective serotonin reuptake inhibitor (SSRI) use with gut microbiome in older adolescents and younger adults.

METHODS

Fifteen to 20-year-old participants within a month of starting an SSRI and unmedicated controls were enrolled in a longitudinal study. They underwent a diagnostic evaluation comprising self-completed and rater-administered questionnaires and clinical interview. They also provided a stool sample, which was stored at -80°C until DNA extraction. Microbial DNA was extracted with the MoBio PowerSoil kit, and the V4 region of the 16S rRNA was amplified and sequenced. Raw sequence data was processed with the LotuS pipeline. Only samples with no antibiotic exposure in the last 6 months and with >1000 quality filtered reads were included in the analysis.

RESULTS

160 participants (57.5% female, mean age 20.0±1.9 years, 29% taking SSRIs) were enrolled, comprising 110 MDD patients (60% in acute episode), 27 healthy controls, and 23 psychiatric controls. No significant group differences were observed in bacterial richness or alpha and beta diversity. Differential abundance analysis of bacterial taxa found no significant group differences at the phylum and genus levels. Neither being in a major depressive episode vs. remission nor using SSRIs was associated with differential bacterial composition.

CONCLUSIONS

In this sizeable sample of older adolescents, neither MDD nor SSRI use was associated with differences in gut bacterial microbiome. In this age group, the bi-directional interaction between the gut bacteria and brain may be more nuanced than in adults, requiring further investigation.

Potential Impact of Climate Change on Human Trafficking: A Narrative Review

ABSTRACT

Climate change is a threat to the public health with wide-reaching impacts that are becoming more studied and recognized. An aspect of climate change that has not yet gained adequate scholarly attention is its potential impact on human trafficking. We review the potential impact of climate change on risk factors to human trafficking including poverty, gender inequality, political instability, migration or forced displacement, and weather disasters. We conclude that climate change is a crucially important consideration in understanding the complex and multifactorial risks for human trafficking. These findings add to the priority for health professionals to embrace efforts to prevent and to mitigate the effects of climate change and to take account of these risk factors in screening and identifying trafficked persons.

Impact of the COVID-19 pandemic on exposure and response prevention outcomes in adults and youth with obsessive-compulsive disorder

The COVID-19 pandemic has created novel mental health challenges for those with pre-existing problems including obsessive-compulsive disorder (OCD). Our study reports on clinician perceptions regarding the effect of the COVID-19 pandemic on patients with OCD receiving exposure and response prevention treatment (ERP) prior to and during the pandemic. Participating clinicians completed a survey which included questions adapted from National Institute of Mental Health-Global Obsessive-Compulsive Scale (NIMH-GOCS) and Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). Clinicians rated clinical features at treatment initiation, just prior to the pandemic, and mid-pandemic (July/August, 2020). Findings suggest that the COVID-19 pandemic was associated with attenuation of ERP progress from expected rates in most patients during first several months of the pandemic; clinicians estimated that 38% of their patients had symptoms worsen during the pandemic and 47% estimated that symptoms remained unchanged despite participating in ERP. Those who endured financial distress or were medically at-risk for severe COVID-19 disease had worse ERP course. Adults also had a worse ERP course during than pandemic than youth. Further research is needed to better understand the effect of the COVID-19 pandemic on OCD symptomatology and treatment trajectory post-pandemic.

Psychological Distress Among the U.S. General Population During the COVID-19 Pandemic

The COVID-19 pandemic is taking a significant global toll on emotional well-being, but evidence of mental health impacts in the United States remains limited. In April 2020, we conducted an exploratory survey of U.S. residents to understand prevalence of and factors associated with psychological distress during the pandemic. Data collection was conducted using Qualtrics, an online survey platform, and U.S. adult respondents were recruited via Amazon's Mechanical Turk platform. Among 1,366 respondents, 42% (n = 571) reported clinically significant anxiety and 38% (n = 519) reported clinically significant depression. Factors associated with anxiety and depressive symptoms included Hispanic/Latino ethnicity; younger age; lower income; employment as or living with a health care worker-first responder; caregiver status; SARS-CoV-2 infection status; decreased frequency of engagement in healthy behaviors; and changed frequency of engagement in unhealthy behaviors. That some of these factors are associated with elevated distress during the pandemic is not yet widely appreciated and might be useful in informing management of mental health care resources.

Polyomaviruses of the skin: integrating molecular and clinical advances in an emerging class of viruses

BACKGROUND

Human polyomaviruses (HPyVs) are small, nonenveloped, double-stranded DNA viruses that express tumour antigen proteins. Fourteen species of polyomaviruses have been discovered in humans, and since the 2008 discovery of the first cutaneous polyomavirus - Merkel cell polyomavirus (MCPyV) - six more species have been detected in the skin: trichodysplasia spinulosa-associated polyomavirus (TSPyV), HPyV6, HPyV7, HPyV9, HPyV10 and HPyV13. Of these cutaneous species, only MCPyV, TSPyV, HPyV6 and HPyV7 have been definitively associated with diseases of the skin, most commonly in immunocompromised individuals. MCPyV is a predominant aetiology in Merkel cell carcinomas. TSPyV is one of the aetiological factors of trichodysplasia spinulosa. HPyV6 and HPyV7 have been recently linked to pruritic skin eruptions. The roles of HPyV9, HPyV10 and HPyV13 in pathogenesis, if any, are still unknown, but their molecular features have provided some insight into their functional biology.

RESULTS

In this review, we summarize the known molecular mechanisms, clinical presentation and targeted therapies of each of the eight cutaneous HPyVs.

CONCLUSIONS

We hope that heightened awareness and clinical recognition of HPyVs will lead to increased reports of HPyV-associated diseases and, consequently, a more robust understanding of how to diagnose and treat these conditions.

Hypermethylation in human cancers of the RIZ1 tumor suppressor gene, a member of a histone/protein methyltransferase superfamily

The retinoblastoma protein-interacting zinc finger gene RIZ1 is a tumor suppressor gene and a member of a nuclear histone/protein methyltransferase superfamily. RIZ1 inactivation is commonly found in many types of human cancers and occurs through loss of mRNA expression, frameshift mutation, chromosomal deletion, and missense mutation. RIZ1 is also a tumor susceptibility gene in mice. We now show that loss of RIZ1 mRNA in human cancers is associated with DNA methylation of its promoter CpG island. Methylation of the RIZ1 promoter strongly correlated with lost or decreased RIZ1 mRNA expression in breast, liver, colon, and lung cancer cell lines as well as in liver cancer tissues. Treatment with the methylation inhibitor 5-aza-2'-deoxycytidine activated RIZ1 mRNA expression in cancer cells. Furthermore, methylation was found in 11 of 25 (44%) breast cancer specimens and 20 of 32 (62%) liver cancer specimens. Our results suggest that DNA methylation is a common mechanism in inactivating the RIZ1 tumor suppressor gene in human liver and breast cancers.

Less reversal of liver fibrosis after prolonged carbon tetrachloride injection

BACKGROUND/AIMS

It was generally believed, but not proved, that early cirrhosis may be reversible, while advanced cirrhosis may not. This present study is to compare in mice the spontaneous regression of liver fibrosis between early and more advanced stage.

METHODOLOGY

Liver fibrosis in mice was induced by intraperitoneal injection of carbon tetrachloride for 4, 10, and 16 weeks. After the last dose of each schedule, mice were sacrificed 1 day later (progression model) or left untreated for 10, 20, and 60 days (regression model). Tissue sections were stained by Sirius red. Liver hydroxyproline levels were determined to assess severity of fibrosis. Gelatinases in tissue extracts were assayed by zymography.

RESULTS

During regression, diminution of fibrotic bands was more prominent in the 4-week group than in the others. Liver hydroxyproline levels in the progression model increased and resolution of liver fibrosis in the regression model decreased as carbon tetrachloride injection was prolonged. Liver matrix metalloproteinase-2 and -9 activities in the progression model also decreased as the injection was prolonged.

CONCLUSIONS

These data demonstrated that reversibility of liver fibrosis would be gradually lost as liver injuries were prolonged. Gradual loss of the expression of matrix metalloproteinases may be responsible for the loss of reversibility.

Expression of matrix metalloproteinases in spontaneous regression of liver fibrosis

BACKGROUND/AIMS

Spontaneous regression of liver fibrosis would depend on the degradation of the excessive matrix in the liver. In this study, we tried to determine the kinetics of the expression of genes for matrix metalloproteinase-2 and -13.

METHODOLOGY

Liver fibrosis induced by carbon tetrachloride was resolved after withdrawal of this toxin. Histological staining for fibrous septa and determination of liver collagen content were used to evaluate the extent of liver fibrosis. Expression in liver of matrix metalloproteinase-2 and -13 was determined by reverse transcription-polymerase chain reaction.

RESULTS

The fibrous septa became thinner and interrupted and liver fibrosis resolved rapidly within 10 days. Expression of matrix metalloproteinase-2 and -13 was elevated to 2.5- and 8.7-fold, respectively, at peak fibrosis. The former was maintained at 88%-76% and the later dropped rapidly to 30%-20% in the recovery periods.

CONCLUSIONS

Resolution of liver fibrosis began within 10 days but only to 70%. Gene expression kinetics suggested metalloproteinase-13 might play a more important role in the resolution because it surged more markedly at peak fibrosis and returned to nearly basal levels in the recovery periods in parallel with liver collagen content.

Deletion mapping of chromosome 16q24 in hepatocellular carcinoma in Taiwan and mutational analysis of the 17-beta-HSD gene localized to the region

Human chromosome band 16q24 commonly undergoes loss of heterozygosity (LOH) in human hepatocellular carcinoma (HCC). To further localize the region of deletion on 16q24 and to evaluate the genetic role of 17-beta-HSD, which is near 16q24, in HCC, we examined the pattern of loss of heterozygosity in 88 HCC patients. DNAs from 88 pairs of HCCs and corresponding non-tumor parts were prepared. Loss of heterozygosity on chromosomes 16q24 was investigated by 11 sets of microsatellite markers. Mutation analysis of type II 17-beta-HSD was performed by automatic sequencing. LOH on 16q24 for at least 1 locus was found in 43 of the 88 tumor DNAs (49%). Three non-overlapping regions of frequent LOH were defined in these 43 tumors with partial deletions. The first region was between D16S516 loci and D16S507, encompassed by a 1-cM region, defined by the D16S504. The second region was defined by the 17HSDB2 locus between D16S505 and D16S422, encompassed approximately by a 1-cM region. The third region was between D16S520 and D16S413, defined by D16S3048, encompassed approximately by a 4-cM region. Homozygous deletions of any exons in 17HSDB2 gene were identified in 7 of 27 cases (26%). Automated sequencing analysis of 17HSDB2 failed to demonstrate mutations in any of these specimens. Our data suggest that the 17HSDB2 locus is a frequent target of deletion in HCC but the inactivation of 17HSDB2 may not involve sequence mutations. Furthermore, the presence of the other 2 frequent LOH regions suggest that the putative tumor suppressor genes at these locations might be involved in the development of HCC.

Expressions of cancer-testis antigens in human hepatocellular carcinomas

Though regular sonographic examination can early detect small hepatocellular carcinoma, the therapeutic results remains unsatisfactory. Antigen-specific immunotherapy is an alternative approach for controlling tumors. The prerequisite for antigen-specific cancer immunotherapy is the identification of appropriate tumor antigens. Recently, a new category of tumor-specific shared antigens, called cancer-testis antigens, has been identified. The cancer-testis antigens have been found in a variety of cancers. However, the expression of cancer-testis antigens in human hepatocellular carcinomas is unknown. The aim of this current study is to investigate the expression of cancer-testis antigens in human hepatocellular carcinomas. Reverse-transcription polymerase chain reaction (RT-PCR) was used to investigate the expression of the SSX-1,-2,-4,-5, SCP-1, NY-ESO-1 genes in tumorous and corresponding non-tumorous liver tissues. In the 30 hepatocellular carcinomas studied, SSX-1,-2,-4,-5, SCP-1, and NY-ESO-1 mRNA expressions were detected in 24 (80%), 14 (46.7%), 22 (73.3%), 10 (33.3%), 2 (6.7%), and 11 (36.7%), respectively. Expressions of these genes were detected in few non-tumor liver tissues. The cancer-testis antigens are expressed in a high percentage of hepatocellular carcinomas. These cancer-testis antigen gene products are potential targets for antigen-specific immunotherapy of hepatocellular carcinoma.

Preferential loss of a polymorphic RIZ allele in human hepatocellular carcinoma

The RIZ (PRDM2) locus commonly undergoes loss of heterozygosity (LOH) and maps within the minimal deleted region on 1p36 in hepatocellular carcinoma (HCC). Although peptide-altering mutations of RIZ are rare in HCC, the RIZ1 product is commonly lost in HCC and has tumour suppressive activities. Here, we analysed RIZ gene mutations and LOH in HCC, breast cancer, familial melanoma, colon cancer, and stomach cancer. We found 7 polymorphisms but no mutations. By analysing the Pro704-deletion polymorphism, we detected LOH of RIZ in 31 of 79 (39%) informative HCC cases, 11 of 47 (23%) colon cancer cases, 8 of 43 (19%) breast cancer cases, 8 of 66 (12%) stomach cancer cases. Importantly, loss of the Pro704(+)allele was found in 74% of the 31 LOH positive HCC cases (P< 0.01), indicating a preferential loss and hence a stronger tumour suppressor role for this allele compared to the P704(-)allele. In addition, the Pro704(+)allele was found to be more common in Asians (0.61) than Caucasians (0.42) (P = 0.0000), suggesting an interesting link between gene polymorphisms and potential differences in tumour incidence between racial groups.

Correlation of histologic subtypes and replication error phenotype with comparative genomic hybridization in gastric cancer

To characterize phenotypic and genotypic changes in gastric cancer (GC), DNA copy number aberrations (CNAs) were assessed in 53 tumors using comparative genomic hybridization (CGH) and correlated with clinicopathologic characteristics and status of TP53 and replication error (RER). The number of CNAs per tumor was 6.8 (gain 5.3, loss 1.5), and the number of changes was significantly higher in tumors with advanced stage, TP53 mutation, and without RER than in those with early stage (7.7 vs. 3.0), no TP53 mutations (12.4 vs. 4.8) or RER phenotype (8.2 vs. 2.6). Frequent abnormalities included gains on chromosomal arms 8q (43%), 6q (26%), 11q (26%), 13q (24%), 7p (23%), 17q (23%), and 20q (23%), and losses on chromosomal arms 16q (26%), 19p (23%), 5q (19%), 3p (15%), 4q(15%), and 1p (15%). Advanced GC demonstrated a higher prevalence of gains of 8q (51% vs. 10%, P < 0.05) and loss of 16q (33% vs. 0%, P < 0.05) than early GC. Gains on 8q (64% vs. 20%, P < 0.05), 17q (39% vs. 4%, P < 0.05) and losses on 3p (25% vs. 4%, P = 0.05) and 5q (32% vs. 4%, P < 0.05) were higher in intestinal GC than in diffuse GC. On the other hand, gains on 13q were more common in the diffuse type (40% vs. 11%, P < 0.05). As compared with noncardia cancer, cardia cancer showed more gains on 7p (58% vs. 12%, P < 0.05) and 20q (58% vs. 12%, P < 0.05) and more losses on 4q (50% vs. 5%, P < 0.05). The finding of histology-related aberrations and the combination of CGH and molecular data thus provide additional evidence suggesting genetic heterogeneity of GC.

Correlation of histologic subtypes and replication error phenotype with comparative genomic hybridization in gastric cancer

To characterize phenotypic and genotypic changes in gastric cancer (GC), DNA copy number aberrations (CNAs) were assessed in 53 tumors using comparative genomic hybridization (CGH) and correlated with clinicopathologic characteristics and status of TP53 and replication error (RER). The number of CNAs per tumor was 6.8 (gain 5.3, loss 1.5), and the number of changes was significantly higher in tumors with advanced stage, TP53 mutation, and without RER than in those with early stage (7.7 vs. 3.0), no TP53 mutations (12.4 vs. 4.8) or RER phenotype (8.2 vs. 2.6). Frequent abnormalities included gains on chromosomal arms 8q (43%), 6q (26%), 11q (26%), 13q (24%), 7p (23%), 17q (23%), and 20q (23%), and losses on chromosomal arms 16q (26%), 19p (23%), 5q (19%), 3p (15%), 4q(15%), and 1p (15%). Advanced GC demonstrated a higher prevalence of gains of 8q (51% vs. 10%, P < 0.05) and loss of 16q (33% vs. 0%, P < 0.05) than early GC. Gains on 8q (64% vs. 20%, P < 0.05), 17q (39% vs. 4%, P < 0.05) and losses on 3p (25% vs. 4%, P = 0.05) and 5q (32% vs. 4%, P < 0.05) were higher in intestinal GC than in diffuse GC. On the other hand, gains on 13q were more common in the diffuse type (40% vs. 11%, P < 0.05). As compared with noncardia cancer, cardia cancer showed more gains on 7p (58% vs. 12%, P < 0.05) and 20q (58% vs. 12%, P < 0.05) and more losses on 4q (50% vs. 5%, P < 0.05). The finding of histology-related aberrations and the combination of CGH and molecular data thus provide additional evidence suggesting genetic heterogeneity of GC.

Hepatocyte growth factor stimulates the growth and activates mitogen-activated protein kinase in human hepatoma cells

Hepatocyte growth factor (HGF) is a potent mitogen for hepatocytes and various epithelial cells. Unexpectedly, it has been reported to inhibit the growth of hepatoma cells in vitro. To clarify this phenomenon, we examined the effects of recombinant baculovirus-expressed HGF on the growth of 6 human hepatoma cell lines. The growth of Hep3B and HepG2 cells was markedly stimulated to 1.8- and 1.7-fold, respectively, PLC/PRF/5 to 1.4-fold, and SK-Hep-1 to 1.2-fold in a dose-dependent manner under HGF concentrations below 20 ng/ml. Neither HuH-7 nor HCC36 were affected. None of these cells were inhibited. All these cells expressed c-Met, the membrane receptor for HGF, and their c-Met would be activated to be phosphorylated upon addition of HGF. They also contained the ERK2 subgroup of mitogen-activated protein kinases (MAPKs). When HGF was added, their ERK2 would also be phosphorylated. The extent of ERK2 phosphorylation was partially correlated to their growth response to HGF. In conclusion, HGF could stimulate the growth of certain human hepatoma cells, probably through activation of c-Met and MAPKs.

Mapping of a minimal deleted region in human hepatocellular carcinoma to 1p36.13-p36.23 and mutational analysis of the RIZ (PRDM2) gene localized to the region

Human chromosome band 1p36 commonly undergoes loss of heterozygosity (LOH) in hepatocellular carcinoma (HCC) but the minimal deleted region remains to be mapped. This chromosomal region contains a candidate HCC suppressor gene, RIZ (PRDM2), that is a member of the PR (PRDI-BF1-RIZ homology)-domain-containing zinc finger gene family. One characteristic of this family is the unusual yin-yang involvement in human cancers. The PR-domain-containing RIZ1 product of the RIZ locus, in contrast to the PR-domain-minus product RIZ2, is commonly lost or underexpressed in HCC. Furthermore, RIZ1 can induce cell cycle arrest, apoptosis, or both and suppress HCC tumorigenicity in nude mice. To help identify the putative HCC locus on 1p36 and to evaluate a genetic role of RIZ in HCC, we studied 97 HCC cases and mapped a minimal deleted region in HCC to 1p36.13-p36. 23 between markers D1S434 and D1S436. Notably, RIZ mapped within this region and was found to undergo LOH in 37% (25/67) of HCC cases. Single-strand conformation polymorphism (SSCP) analysis, however, did not show mutations in the PR-domain region of RIZ1 in 49 cases of HCC examined. Our data suggest that the RIZ locus is a target of frequent deletion in HCC, but that the more common way of RIZ inactivation in HCC may not involve mutations that alter peptide sequences. Genes Chromosomes Cancer 28:269-275, 2000.

Mapping of a minimal deleted region in human hepatocellular carcinoma to 1p36.13-p36.23 and mutational analysis of the RIZ (PRDM2) gene localized to the region

Human chromosome band 1p36 commonly undergoes loss of heterozygosity (LOH) in hepatocellular carcinoma (HCC) but the minimal deleted region remains to be mapped. This chromosomal region contains a candidate HCC suppressor gene, RIZ (PRDM2), that is a member of the PR (PRDI-BF1-RIZ homology)-domain-containing zinc finger gene family. One characteristic of this family is the unusual yin-yang involvement in human cancers. The PR-domain-containing RIZ1 product of the RIZ locus, in contrast to the PR-domain-minus product RIZ2, is commonly lost or underexpressed in HCC. Furthermore, RIZ1 can induce cell cycle arrest, apoptosis, or both and suppress HCC tumorigenicity in nude mice. To help identify the putative HCC locus on 1p36 and to evaluate a genetic role of RIZ in HCC, we studied 97 HCC cases and mapped a minimal deleted region in HCC to 1p36.13-p36. 23 between markers D1S434 and D1S436. Notably, RIZ mapped within this region and was found to undergo LOH in 37% (25/67) of HCC cases. Single-strand conformation polymorphism (SSCP) analysis, however, did not show mutations in the PR-domain region of RIZ1 in 49 cases of HCC examined. Our data suggest that the RIZ locus is a target of frequent deletion in HCC, but that the more common way of RIZ inactivation in HCC may not involve mutations that alter peptide sequences. Genes Chromosomes Cancer 28:269-275, 2000.

Recurrent hepatocellular carcinoma presenting with superior vena cava syndrome

A 45-year-old male received wedge resection for his small hepatocellular carcinoma in April 1989 and extended right lobectomy for tumor recurrence 8 months later. Unfortunately, recurrent hepatic tumor with lung metastases were found 18 months after the second operation. Both the hepatic and pulmonary recurrent tumors were resected and transcatheter arterial embolization was added for the residual hepatic tumors. He remained symptom free for another 18 months. However, mediastinal lymphadenopathy, superior vena cava thrombus with superior vena cava syndrome, cardiac and brain metastases developed subsequently. He died of increased intracranial pressure. It is rare for hepatocellular carcinoma to have mediastinal metastases, superior vena cava thrombus and superior vena cava syndrome.

Distinct clinicopathologic and genetic profiles in sporadic gastric cancer with different mutator phenotypes

A subset of sporadic gastric cancers (GC) exhibits microsatellite instability (MSI). To define the precise role of MSI in GC, a total of 100 patients with sporadic GC were classified into three groups, i.e., high-frequency MSI (MSI-H), low-frequency MSI (MSI-L), and microsatellite stable (MSS), based on 10 microsatellite markers. Mutational analyses of TGFbetaRII, IGFIIR, BAX, MSH3, MSH6, E2F4, MSH2, MLH1, and TP53 genes, and methylation and protein expression of MLH1 and MSH2 were performed and correlated. Twenty-seven percent of GC showed MSI at least in one locus and could be further graded as MSI-H (14%) and MSI-L (13%). No clinicopathologic difference was noted between GC with MSI-L and MSS. Compared with GC with MSI-L or MSS, GC with MSI-H had a significantly higher frequency of antral location, intestinal subtype, H. pylori seropositivity, but a lower incidence of lymph node metastasis, and displayed a higher frequency of frameshift mutations of TGFbetaRII, IGFIIR, BAX, MSH3, and E2F4 genes but a lower incidence of TP53 mutations. Furthermore, hypermethylation of the MLH1 promoter was responsible for the loss of protein function in 13 of 14 MSI-H tumors. It was concluded that a specific phenotype and a distinct profile of genetic alterations exist in MSI-H GC. We speculate that epigenetic inactivation of MLH1 by methylation plays a crucial role in initiating such a pathway of carcinogenesis. In contrast, GCs with MSS and MSI-L exhibit clinicopathologic features that are distinct from MSI-H tumors and have a higher frequency of TP53 mutations, suggesting that they may evolve through an entirely different pathway.

Distinct clinicopathologic and genetic profiles in sporadic gastric cancer with different mutator phenotypes

A subset of sporadic gastric cancers (GC) exhibits microsatellite instability (MSI). To define the precise role of MSI in GC, a total of 100 patients with sporadic GC were classified into three groups, i.e., high-frequency MSI (MSI-H), low-frequency MSI (MSI-L), and microsatellite stable (MSS), based on 10 microsatellite markers. Mutational analyses of TGFbetaRII, IGFIIR, BAX, MSH3, MSH6, E2F4, MSH2, MLH1, and TP53 genes, and methylation and protein expression of MLH1 and MSH2 were performed and correlated. Twenty-seven percent of GC showed MSI at least in one locus and could be further graded as MSI-H (14%) and MSI-L (13%). No clinicopathologic difference was noted between GC with MSI-L and MSS. Compared with GC with MSI-L or MSS, GC with MSI-H had a significantly higher frequency of antral location, intestinal subtype, H. pylori seropositivity, but a lower incidence of lymph node metastasis, and displayed a higher frequency of frameshift mutations of TGFbetaRII, IGFIIR, BAX, MSH3, and E2F4 genes but a lower incidence of TP53 mutations. Furthermore, hypermethylation of the MLH1 promoter was responsible for the loss of protein function in 13 of 14 MSI-H tumors. It was concluded that a specific phenotype and a distinct profile of genetic alterations exist in MSI-H GC. We speculate that epigenetic inactivation of MLH1 by methylation plays a crucial role in initiating such a pathway of carcinogenesis. In contrast, GCs with MSS and MSI-L exhibit clinicopathologic features that are distinct from MSI-H tumors and have a higher frequency of TP53 mutations, suggesting that they may evolve through an entirely different pathway.

Incidence and clinical presentation of posttransfusion TT virus infection in prospectively followed transfusion recipients: emphasis on its relevance to hepatitis

BACKGROUND

A novel transfusion-transmissible human DNA virus, TT virus (TTV), has been discovered recently. An attempt was made to determine the incidence and clinical outcome of TTV infection in recipients of blood transfusion.

STUDY DESIGN AND METHODS

Serial serum samples collected as part of a prospective study of posttransfusion hepatitis were examined for TTV DNA by a nested PCR assay.

RESULTS

Among 150 adults undergoing cardiac surgery, posttransfusion specimens from 59 individuals were positive for TTV DNA. Pretransfusion sera were found to be positive in 13 of these individuals. Therefore, 46 (33.6%) of the 137 previously uninfected patients developed new TTV viremia after transfusion. Among the 46 patients, 3 were coinfected with HCV, 5 were coinfected with HGV, and 38 were infected with TTV alone. No apparent symptoms or signs were noted in the 38 patients infected by TTV alone or the 5 infected with HGV plus TTV. The average peak serum ALT activity was 31 IU per L, with persistently normal levels in 34 of the 38 patients with TTV infection alone. In 8 other patients who subsequently developed well-documented non-A-G hepatitis, 3 were positive for TTV (3/8 vs. 46/137, p = 0.8). In 12 patients followed for more than 1 year, TTV viremia persisted in every case.

CONCLUSION

In this population, TTV is transmitted by transfusion to approximately 30 percent of patients who undergo cardiac surgery. Most of the infections appear to become persistent. Despite the high prevalence rate, TTV does not appear to cause hepatitis on its own.

Dilatation of the biliary tree in children: sonographic diagnosis and its clinical significance

We evaluated sonographically 162 children who met the criteria for biliary tract dilatation in the past 18 years. Of these, 131 patients were diagnosed as having anomalous dilatations of the biliary tree (including 112 with choledochal cysts and 19 with biliary duct dilatation and biliary atresia). Biliary tract dilatations in the other 31 patients were due to secondary causes or normal variants. All cases of intrahepatic biliary tree dilatation and those with both intra- and extrabiliary duct dilatations were anomalous. In 117 cases of extrahepatic biliary tract dilatation only, the mean diameter was widest in cases of choledochal cyst (21.4 +/- 12.1 mm, compared with cases of biliary tract dilatation with biliary atresia (10 +/- 2.4 mm), secondary biliary duct dilatation (8.5 +/- 1.5 mm), and normal variants (4.4 +/- 1.2 mm) (P < 0.001). Of the 43 infants with biliary tree dilatation, 24 (56%) had choledochal cysts and 19 (44%) had biliary tract dilatation associated with biliary atresia. Excluding cases associated with biliary atresia, the accuracy of diagnosing choledochal cysts in extrahepatic biliary tract dilatation was 71% and 97% using cutoffs of 7 mm and 10 mm as the minimum diameter, respectively.

Segmental dilatation of the ileum as an unusual cause of gastrointestinal bleeding: report of one case

We report a case of segmental dilatation of the ileum in a 10-month-old male infant. Intermittent loose black-colored stool passage and normocytic anemia were noted at the initial visits to our hospital. There was no symptom or sign of intestinal obstruction such as abdominal distention or vomiting. On physical examination, he was found to be pale but his abdomen was soft and flat. Digital examination revealed brownish stool tinged with black-colored oil-like stool but no polyp. Laboratory studies excluded coagulopathy, hemolytic anemia and lead poisoning. During hospitalization, he was treated with nothing per mouth, intravascular fluids, ranitidine, and transfusion of packed red blood cells. All examinations including panendoscopy, Technetium-99m (99mTc)-pertechnetate Meckel's diverticulum scan, and double contrast colon series revealed no organic lesion except that 99mTc-red blood cell bleeding scans showed abnormal bleeding in the small intestine. Because of his persistent gastrointestinal bleeding with unknown cause, we did an exploratory laparotomy when the patient was 13 months old and idiopathic segmental dilatation of the ileum was confirmed. The dilated segment is supposed to be idiopathic because of histologically proven normal muscle layers without ectopic tissue. This case suggests that segmental dilatation of the ileum can only present as gastrointestinal bleeding without intestinal obstruction.

Hepatic lymphangioma--a case report

A patient presented with a huge, pedunculated abdominal cystic lymphangioma arising from the quadrate lobe of the liver near the round ligament. Microscopically, dilated hepatic ducts with scant liver tissue could be recognized in the main cyst. A review of the literature reveals no previous report of a lymphangioma arising in this manner or from this area.

Loss of heterozygosity at chromosome 13q in hepatocellular carcinoma: identification of three independent regions

Loss of heterozygosity (LOH) on chromosome 13q is one of the most common genetic alterations in hepatocellular carcinoma (HCC) and might be involved in liver cancer development through inactivation of tumour suppressor genes. In order to narrow down the region of 13q loss, we examined the pattern of loss of heterozygosity (LOH) in tumours from 88 HCC patients, using 18 microsatellite markers on 13q. Thirty-eight of the 88 tumours (43%) showed LOH for at least one marker. Of these, two tumours (5%) showed 13q whole arm allelic loss, while the remaining 36 tumours (95%) had partial allelic loss. The LOH pattern defined by the 36 tumours suggested the existence of at least three different smallest common deleted regions which might be involved in the carcinogenesis of HCC. The first, the most centromeric in the 13q12.3 is, close to the BRCA2 gene, defined by D13S171; the second, the most telomeric region in the 13q31-32 band, is defined by D13S154 and D13S157; the third, the intermediate region at 13q14.3, which is near the RB gene, is defined by loci D13S268. The rate of LOH at 13q31-32 was significantly higher in Hepatitis B-surface antigen (HBsAg)-positive patients than HBsAg-negative HCC patients, pointing to a candidate gene related to the development of HBsAg-positive HCCs.

A different experience of hepatic adenoma in Taiwan with emphasis on clinical manifestations and ultrasonographic features

BACKGROUND/AIMS

Hepatic adenoma is a rare benign hepatic tumor and it is difficult to differentiate it from other focal hepatic tumors. Ultrasonography has become the choice of methods to detect focal hepatic lesions. The study aims at analyzing ultrasonographic features of hepatic adenoma.

METHODOLOGY

A total of 8 patients with pathologically proven hepatic adenoma were studied retrospectively during an 8-year period. The ultrasound scanners used were Toshiba SSA-100A, Toshiba SSA-240 and Aloka 630. The ultrasonographic features and clinical data were analyzed.

RESULTS

There were 7 males and 1 female. The mean age was 50 years. Of the 8 cases, 2 symptomatic cases had a tumor larger than 10 cm. The remaining 6 cases were asymptomatic and had tumors smaller than 5 cm. The echogenicity was variable in these tumors. An irregular sonolucent was only noted in a 15 cm tumor and was histologically proven to be internal bleeding. All the tumors were well-defined, however, a hypoechoic rim was obvious only in the isoechoic and hyperechoic tumors.

CONCLUSIONS

Ultrasonographic features of some hepatic adenomas are different from those of hepatocellular carcinomas and hemangiomas, although the differential diagnosis cannot be made in small hypoechoic tumors. When ultrasonography is used more widely, more asymptomatic patients with small-sized hepatic adenoma will be detected, even in male subjects. The concept about the pathogenesis of hepatic adenomas may be changed.

Pancreatic tumors in children: report of three cases

From 1981 to 1996, we experienced 3 cases of pancreatic tumors in children--two pancreatoblastomas (PB) and one solid and cystic tumor (SCT). The ages were 1 month, 4 years, and 13 years of age respectively. The two cases of pancreatoblastoma initially presented as chronic diarrhea with failure to thrive, the other case presented with abdominal mass. All of them were studied by laboratory examination, ultrasonography, computed tomography and pathology. Increasing alpha- fetoprotein (AFP) levels were found in the 2 pancreatoblastoma cases, however, the level in the SCT case was normal. Abdominal sonography showed pancreatic masses with or without calcification, and the echogenicity may be solid and/or cystic. All patients underwent total excision of the tumors. We have reviewed the literature and find no pancreatoblastoma with chronic diarrhea was reported in young children, especially in neonate. Therefore, we suggest that young children presenting with an abdominal mass and/or weight loss should undergo imaging studies for the possibility of pancreatic tumors.

Bacterial infections associated with hepatic arteriography and transarterial embolization for hepatocellular carcinoma: a prospective study

Sepsis and liver abscess are serious complications following transarterial embolization (TAE) for hepatocellular carcinoma (HCC). However, the exact incidence and the necessity of antibiotic prophylaxis remain undetermined. Between November 1996 and November 1997, we prospectively studied bacterial infections in 231 HCC patients who underwent 287 angiographic procedures without antibiotic prophylaxis, including 176 TAEs and 111 hepatic arteriographies (HAs). Four of the 111 HAs were complicated by transient asymptomatic bacteremia. Of the 176 TAEs, 2 were associated with asymptomatic bacteremia, and 7 (4%) were associated with symptomatic bacterial infection, including 3 cases of sepsis, 2 of liver abscess, and 2 of infected biloma. For patients with HCC, TAE was associated with a higher risk of developing symptomatic bacterial infections than was HA (4% vs. 0, respectively; P = .03). Previous gastrectomy was the only possible risk factor for liver abscess. Finally, early diagnosis and treatment of these infectious complications usually result in successful outcome.

Correlation of E-cadherin expression and recurrence of hepatocellular carcinoma

BACKGROUND/AIMS

We performed this study to clarify the relationship between E-cadherin expression and recurrence of hepatocellular carcinoma.

METHODOLOGY

Forty-five surgically resected specimens of hepatocellular carcinoma were collected. The patients included 35 men and 10 women. The ages were between 30 and 77 years, with a mean age of 54 years. Western blotting and/or immunohistochemical staining of the tumor and non-tumor tissues for detection of E-cadherin were performed. Reverse transcription-polymerase chain reaction to check the levels of mRNA for E-cadherin and nucleotide sequencing of putative calcium binding domains were done if the tumor tissues showed negative E-cadherin expression.

RESULTS

Three (6.7%) tumor tissues were negative for E-cadherin with both Western blotting and immunohistochemical staining. Of the 3, two showed decreased mRNA in tumor tissues while the other 10 randomly selected samples did not show this phenomenon. No mutation of nucleotide sequence in the putative calcium binding domains was found. Two of the 3 patients had invasive cancers by histological studies while 13 out of the other 42 E-cadherin positive cases showed invasive cancers.

CONCLUSIONS

E-cadherin underexpression might have some contribution to the early recurrence of hepatocellular carcinoma. Transcriptional or post-transcriptional down-regulation may be the mechanism of underexpression of E-cadherin in hepatocellular carcinoma.

Serum hepatocyte growth factor before and after resection for hepatocellular carcinoma

BACKGROUND/AIMS

Hepatocyte growth factor (HGF) is the most potent hepatocyte proliferation stimulator. Serum HGF levels are high in various liver disease states such as cirrhosis, hepatocellular carcinoma (HCC) and hepatitis. But the role HGF plays in HCC is not clear at present. The purposes of this study are: 1) to reveal the HGF profile pre- and post-HCC resection, which has not been well-described before; and, 2) to analyze the relationships between the pre- and post-operative HGF levels and various clinical parameters.

METHODOLOGY

We performed a retrospective cohort study to check the HGF profiles before and after curative resections for HCC and to analyze the relationships between them by using clinical parameters from 35 consecutive patients at the Department of Surgery, National Taiwan University Hospital. Blood samples collected from another 23 healthy individuals admitted for health check-ups were used as normal controls. Serum HGF was determined with an ELISA kit.

RESULTS

The baseline HGF concentration in HCC patients was significantly higher than that in normal controls (1743+/-73 vs. 948+/-54 pg/ml, p<0.0001). The HGF concentrations on post-operative days (POD) 1, 3, 5, 7, and 14 were all significantly higher than those seen in normal controls (all p less than 0.0001). The first and third POD HGF values were significantly higher than the pre-operative level (p=0.00135 and 0.00187 respectively). The HGF concentrations would return to the pre-operative level on the fifth POD, but they never returned to normal level at the end of the two-week study. The pre-operative HGF level was affected by patient age (p=0.0236), and the post-operative peak HGF level was positively correlated with the pre-operative indocyanin green retention rate (ICGR15) and GOT level (p=0.0320 and 0.0234 respectively).

CONCLUSIONS

In this study, we proved, indirectly, that HGF was not secreted by the HCC tumor cells per se. The peak post-operative HGF level reflected the relative stress of the operation on the diseased liver, but did not reflect the absolute physical extent of liver resection. The relationships between HGF and the prognosis of the patients after HCC resection demands further investigation.

Loss of heterozygosity and microsatellite instability in hepatocellular carcinoma in Taiwan

Elucidation of the basic genetic changes of human hepatocellular carcinoma is important for the understanding and treatment of this cancer. We used microsatellite polymorphism markers to study 30 cases of hepatocellular carcinoma (34 tumours) on all human chromosomes. DNA from 34 pairs of hepatocellular carcinomas and corresponding non-tumour parts was prepared. Loss of heterozygosity (LOH) and microsatellite instability on 23 chromosomes were investigated by 231 sets of microsatellite markers. More than 20% LOH was shown for loci on 16q (47.1%), 13q (32.4%), 17p (32.4%), 5q (26.5%), 11p (23.5%) and 9p (20.6%). The commonly affected regions were mapped to 16q12.1, 16q12.2, 16q24, 13q12.1-32, 17p13, 5q32, 5q34, 5q3, 11p15, 11q23-24 and 9p21. Hepatitis B virus carriers had a significantly higher frequency of LOH on chromosomes 5q, 11p and 16q. Furthermore, larger tumour size tended to have higher frequency of LOH at D16S409 locus (16q12.1). Microsatellte instability was only found in 12 of 231 markers and the frequency is very low. These data suggest that the chromosomes 16q, 13q, 17p, 5q, 11p and 9p might participate in hepatocarcinogenesis. However, microsatellite instability might play little role in the development of this cancer in Taiwan.

Prenatal sonographic detection of adrenal hemorrhage confirmed by postnatal surgery

We report a case of adrenal hemorrhage in a newborn first detected by sonography at a menstrual age of 21 weeks 4 days. An echogenic mass was noted above the right kidney. The mass became larger and hypoechoic on follow-up sonograms after birth. The mass was also seen on abdominal CT. Because it was difficult to differentiate the lesion from cystic neuroblastoma and because it shrank only modestly by 2 months after birth, we performed a surgical exploration when the patient was 2 months old, and adrenal hemorrhage was confirmed. This case suggests that adrenal hemorrhage can occur as early as the second trimester of pregnancy.

High frequency of expression of MAGE genes in human hepatocellular carcinoma

AIMS/BACKGROUND

Activation of human MAGE genes leads to the expression of a set of tumor rejection antigens, which are recognized by cytotoxic T lymphocytes. The antigens may become the targets of immunotherapy. The expression of MAGE genes was originally found in, but is not restricted, to melanomas. The aim of this study was to investigate the expression of MAGE genes in human hepatocellular carcinomas.

METHODS

The expression of MAGE-1, -2, -3, -4 genes in tumorous and corresponding non-tumorous liver tissue was studied using a reverse-transcription polymerase chain reaction.

RESULTS

In the 50 hepatocellular carcinomas studied, MAGE-1, -2, -3, -4 mRNA expression was detected in 23 (46%), 17 (34%), 21 (42%) and 8 (16%), respectively. Seventy-four percent of the hepatocellular carcinomas expressed at least one of the MAGE genes. MAGE mRNAs were not detected in the corresponding non-tumor liver tissues. MAGE gene expression was not significantly correlated with clinicopathological factors.

CONCLUSIONS

The MAGE genes are expressed in a high percentage of hepatocellular carcinomas; the MAGE gene products are potential targets for tumor-specific immunotherapy.

Chromosomal abnormality in hepatocellular carcinoma by comparative genomic hybridisation in Taiwan

The elucidation of the genetic changes of hepatocellular carcinoma (HCC) is very important for understanding the molecular mechanism of liver carcinogenesis. In order to identify the gains or losses in DNA sequence copy number in HCC, we used comparative genomic hybridisation to study 40 cases (44 tumours) of HCC. Tumour DNA and DNA from non-neoplastic liver tissue were labelled with different fluorochromes and then simultaneously hybridised to normal metaphase spread chromosomes. An image acquisition system was used to quantitate signal intensities contributed by tumour and reference DNA along the entire length of each chromosome. Regions of amplification and deletion were demonstrated as quantitative alterations. Losses were prevalent on chromosome regions 16q (43%), 17p (20%), 13q (20%), 4q (15%) and 8p (15%). Gains frequently occurred on 8q (30%), 1q (20%), 6p (20%) and 17q (18%). Hepatitis B virus carriers had a significantly higher frequency of losses on chromosome 16q. Furthermore, the minimal region of losses was narrowed down to 16q11-q22. This study confirms the presence of previously known chromosomal aberrations in HCC and highlights a new significant correlation between losses on chromosome 16q and hepatitis B virus carriers.

Favorable outcome in a fetus with an early-onset extensive cystic hygroma colli and intralesional hemorrhage

We present a rare occurrence of an early-onset extensive cystic hygroma colli with intralesional hemorrhage and a favorable outcome. A 23-year-old primigravida woman was referred for management of a left isolated extensive cystic hygroma colli at 22 weeks' gestation. Amniocentesis revealed a 46, XY karyotype. Ultrasound-guidance in utero paracentesis was performed weekly or fortnightly from 22 to 36 gestational weeks. The aspirated fluid was chocolate-colored and contained abundant lymphocytes, erythrocytes, and protein. Despite multiple aspirations, the fetal cystic hygroma colli increased in size from 5.2x4.2 cm at 22 weeks' gestation to 9x9.7 cm at 36 weeks' gestation. The woman underwent cesarean section at 36 week's gestation and a-2808 g neonate was born with a 10x6 cm left neck mass, which did not impair spontaneous normal respiration. At the age of 4 days, the neonate underwent simple excision of the cystic hygroma, which was confined to the anterior superficial neck. The neonate was discharged 4 days after operation in good condition. In the present case, in utero paracentesis did not prevent the progressive growth of an early-onset extensive cystic hygroma colli with intralesional hemorrhage. However, lack of extension of the lesion into the surrounding structures and successful postnatal surgery contributed to the favorable outcome of this patient.

Tissue hepatocyte growth factor and proliferating cell nuclear antigen in hepatocellular carcinoma

To better understand the roles of hepatocyte growth factor (HGF) and proliferating cell nuclear antigen (PCNA) in hepatocellular carcinoma (HCC), 37 surgically resected HCCs and corresponding nontumorous liver tissue specimens were collected and the expression of these two factors was quantified by Western blot analysis. Both HGF and PCNA expression levels were significantly higher in tumor tissue than in nontumorous liver tissue. However, their expression levels in HCC tissue and nontumorous tissue did not show any significant correlation with the recurrence of HCC. In addition, HGF and PCNA did not correlate with Edmondson's grade, invasiveness of tumor, presence of tumor capsule, or tumor size. No correlation was found between the expression levels of HGF and PCNA in HCC tissue. We conclude that, although both HGF and PCNA are present at higher levels in HCC tissue than in nontumorous liver tissue, they play little role in the clinicopathologic manifestations of this tumor. HGF appears to contribute little, if at all, to the proliferative activity of HCC cells.

Intrahepatic bilomas associated with hepatic arteriovenous malformation

A 26 year-old female presented with progressive intermittent right upper quadrant pain. Hepatic arteriovenous malformation with small intrahepatic bilomas were found. She underwent hepatic artery ligation for control of her abdominal pain. Though the abdominal pain subsided after the hepatic artery ligation, the intrahepatic bilomas progressed. It is possible that the hepatic arteriovenous malformation (AVM) might reduce blood flow to the bile duct and then induce ischemia in the peribiliary capillary plexus, thus leading to bile duct necrosis and formation of bilomas, which could be further aggravated by hepatic artery ligation.

Telomerase activity and telomere length in human hepatocellular carcinoma

Telomerase activity is activated and telomere length altered in various types of cancers, including hepatocellular carcinoma (HCC). A total of 39 HCC tissues and the corresponding non-tumour livers were analysed and correlated with clinical parameters. Telomere length was determined by terminal restriction fragment assay, and telomerase activity was assayed by telomeric repeat amplification protocol. Telomerase activity was positive in 24 of the 39 tumour tissues (1.15-285.13 total product generated (TPG) units) and in six of the 39 non-tumour liver tissues (1.05-1.73 TPG units). In the 28 cases analysed for telomere length, telomere length was shortened in 11 cases, lengthened in six cases, and unaltered in 11 cases compared with non-tumour tissues. Neither telomere length nor telomerase activity was correlated to any clinical parameters.

Perinatal findings in a male fetus with congenital megacystis and anorectal malformations

We report the perinatal findings in a male fetus with congenital megacystis and anorectal malformations. A 17-year-old primipara was referred to our department at 13 weeks of gestation for management of a 4.6 x 3.8 cm massive intra-abdominal fetal mass consistent with megacystis. The fetal thorax was severely compressed. We used a 22-gauge needle to perform intrauterine fetal vesicocentesis, removing 30 ml of fetal urine, decreasing the fetal bladder diameter/crown-rump length ratio from 65.7 to 17%. Cytogenetic analysis revealed a 46, XY karyotype. Intermittent bladder aspiration was performed weekly from 13 to 20 weeks of gestation and every 2-3 weeks from 21 to 35 weeks of gestation for the purpose of decompression. Mild dilation of both renal pelves was noted beginning at 20 weeks of gestation, however, neither progression of hydronephrosis nor development of oligohydramnios was noted. At 36 weeks of gestation, a live male neonate was delivered with a normal phallus, duodenal atresia, mild congenital heart defects, a distended bladder, bilateral hydronephrosis, megaureters, imperforate anus with rectovesical fistula, cryptorchidism and bilateral vesicoureteric reflux. The postnatal renal function was normal. He underwent serial operations including colostomy, anoplasty with repair of rectovesical fistula, duodeno-duodenostomy, bilateral re-implantation of ureters, orchiopexy and reduction cystoplasty. At 20 months of age, the child had normal renal function. The intravenous pyelogram showed normal functional kidneys, moderate megaureters and moderate megacystis. He underwent clean intermittent catheterization for residual urine. The recurrent urinary tract infections were under control.

Infrequent mutations and no methylation of CDKN2A (P16/MTS1) and CDKN2B (p15/MTS2) in hepatocellular carcinoma in Taiwan

CDKN2A (p16INK4A/MTS1) and CDKN2B (p15INK4B/MTS2) have recently been shown to be potent inhibitors of the cyclin D/cyclin-dependent kinase-4 complex. Both genes are candidates for the putative tumour suppressor genes located at chromosome 9p21 and are frequently inactivated in many human cancers through homozygous deletion. More recently, another reported pathway of inactivation involves loss of transcription associated with de novo methylation of the 5' CpG island of p16/MTS1 and p15/MTS2 in human cancers. We examined a total of 34 tumours from 30 hepatocellular carcinoma (HCC) patients for deletion, mutation and DNA methylation of these two genes by polymerase chain reaction (PCR) amplification, sequence analysis and Southern blot. Homozygous deletions of P16/MTS1 exon 1 were only identified in 1 of 30 cases (3%). Homozygous deletions of p15 exon 1 or exon 2 were found in 7 of 30 cases (13%). Automated sequencing analysis of p16 exon 1 and 2 and p15 exon 1 and 2 failed to demonstrate mutations in either p16 or p15 in any of these specimens. No aberrant 5' CpG island hypermethylation of p16 or p15 was found in any of the primary tumours by Southern blot. These data suggest that the p16/MTS1 gene has a limited role in HCC. However, deletions of the p15/MTS2 gene are found in 13% HCC and might be involved in a subset of HCC.

Overexpression of p53 in different subtypes of intestinal metaplasia and gastric cancer

p53 immunostaining was evaluated in cancerous epithelia and adjacent intestinal metaplasia of 135 gastric cancer specimens. The differential p53 overexpression in different subtypes of intestinal metaplasia and gastric cancer suggests that type III intestinal metaplasia is the commonest lesion in dysplasia-carcinoma transition, particularly in the intestinal type of gastric cancer.

Clinical impact of screening first-degree relatives of patients with hepatocellular carcinoma

Family history is a risk factor for hepatocellular carcinoma (HCC). However, the risk of first-degree relatives is not known. To investigate the risk of HCC among the first-degree relatives of probands and whether screening can lead to early diagnosis of HCCs in these relatives, we conducted a screening program. The probands' first-degree relatives who were >20 years old were included. Serum aminotransferase, hepatitis viral marker, alpha-fetoprotein, and abdominal sonography were done. HCCs were found in 20 (1.9%) of the 1,046 first-degree relatives, especially in the male siblings. Eighty-five percent of these 20 HCC patients were hepatitis B virus carriers. Forty percent of these 20 HCC patients had tumors <5 cm. Approximately 55% of these 20 HCCs were resectable. The 1-year survival rate in these 20 HCC patients with resectable HCCs was 72.7%. However, the overall 1-year survival rate was only 40%. We found HCC in 1.9% of the first-degree relatives of HCC patients. The male relatives, especially the older brothers, were the group at highest risk. The familial HCCs were closely related to the hepatitis B virus infection. To detect HCCs early, initial screening should be done as early as possible on the HCC family members.

Is surgery necessary for primary non-refluxing megaureter?

From January 1990 to December 1995, a total of 22 patients with primary non-refluxing megaureter were treated in our hospital. The age distribution was 7 days to 8 years. The follow-up period was from 1 to 6 years. Nineteen of these 22 children underwent surgical intervention: 3 were operated upon at the time of diagnosis; the other 16 were initially treated conservatively, but underwent subsequent surgery due to impairment of renal function (13) or breakthrough infections (3). The failure rate for conservative management was about 84% (16/19): only 3 patients treated conservatively showed spontaneous resolution. The surgical success rate was 89.5% (17/19). The pathological change in the ureterovesical junction (UVJ) was adynamic in 13 cases and fibrotic in 6 (including 1 ectopic ureter). The postoperative complications were vesicoureteric reflux in 3 cases, with spontaneous resolution 6 months later, and UVJ stenosis in 1, which was resolved by reoperation. It is concluded that surgery is not necessary in every case, but still plays an important role in most cases. Early surgery can achieve good results and reduce renal damage.

Conservative treatment of intra-abdominal abscess in children

Fifty-three children under 18 years of age with sonogram-proved intra-abdominal abscess (IAA) were seen between July 1993 and June 1996 at the Department of Pediatrics of the Mackay Memorial Hospital, then were studied retrospectively. Following a course of conservative treatment and follow-up with serial sonographic studies, 42 (79.3%) patients responded favourably to antibiotics treatment without drainage procedure. The other 11 patients' condition deteriorated, and surgical intervention was performed. The gradual shrinkage and completely resolved periods of the abscesses averaged 27.9 days. The average duration of antibiotic treatment was 23.6 days, intravenously for average 12.2 days followed by oral treatment until the abscess was completely resolved (average 11.4 days). The intra-abdominal abscess recurred in 3 (5.7%) patients. The experience demonstrates that pediatric patients with an intra-abdominal abscess must be followed closely by sonography, and they can be managed successfully with appropriate antibiotics alone. Surgical intervention is still needed if symptoms and signs persist or deteriorate.

Differential tyrosine phosphorylation/activation of oncogenic proline-directed protein kinase F(A)/GSK-3alpha in well and poorly differentiated human prostate carcinoma cells

Computer analysis of protein phosphorylation site sequences revealed that transcriptional factors and viral oncoproteins are prime targets for regulation of proline-directed protein phosphorylation, suggesting an association of the proline-directed protein kinase (PDPK) family with neoplastic transformation and tumorigenesis. In this report, an immunoprecipitate activity assay of proline-directed protein kinase F(A)/glycogen synthase kinase-3alpha (PDPK F(A)/GSK-3alpha) has been optimized to demonstrate significantly increased (p < 0.01) activity in poorly differentiated human prostate carcinoma PC-3 cells (55.5+/-3.8 units/mg) when compared to well-differentiated LNCaP cells (28.1+/-2.3 units/mg). Immunoblotting analysis revealed that increased activity of this PDPK in PC-3 cells is due not to overexpression of the protein, but to enhanced tyrosine phosphorylation of the kinase. When treated with genistein (a protein tyrosine kinase PTK inhibitor), the enhanced tyrosine phosphorylation/activation of the kinase in PC-3 cells can be blocked. Conversely, when treated with vanadate (a protein tyrosine phosphatase PTP inhibitor), the phosphotyrosine content of PDPK F(A)/GSK-3alpha in LNCaP cells can be promoted to the level of PC-3 cells. In sharp contrast, the PTK inhibitor has little effect on the tyrosine phosphorylation level of the kinase in LNCaP cells, whereas the PTP inhibitor has little effect on the tyrosine phosphorylation level of the kinase in PC-3 cells. Taken together, the results provide initial evidence that the tyrosine phosphorylation/activation levels of this oncogenic PDPK can be differentially regulated in well- and poorly differentiated prostate carcinoma cells.

The stage I yolk sac tumor of testis in children younger than 2 years, chemotherapy or not?

Yolk sac tumor is the most frequent germ cell tumor of testis in children. For stage I yolk sac tumor of testis in children younger than 2 years, high inguinal orchiectomy alone has been the standard treatment, with a cure rate of at least 75%. Here, we compare the treatment results of receiving chemotherapy or no chemotherapy after orchiectomy, to analyze the role of chemotherapy. From February 1987 to January 1997, 22 children younger than 2 years, with stage I yolk sac tumor of testis, were included in the study. All patients had high inguinal orchiectomy without retroperitoneal lymphadenectomy. Initial diagnostic imaging studies included computed tomographic scan of abdomen, chest radiography, and long bone survey. Clinical stage I was defined as a tumor completely resected with no evidence of local regional lymph node involvement or distant metastases. Serum alpha-fetoprotein (AFP) was assessed at diagnosis. After orchiectomy, diagnosis, and staging, patients were stratified into two treatment groups, with or without chemotherapy, according to the decision of the parents. Ten children received chemotherapy consisting of cisplatin, vinblastine, and bleomycin (PVB, modified "Einhorn regimen") for 12 weeks. The remaining 12 patients were followed up according to a "wait and see" policy. Determination of AFP was performed monthly during the first postoperative year, every other month during the second year, every 3 months during the third year, every 6 months during the fourth year, and yearly until the fifth postoperative year at least. The duration of follow-up ranged from 3 months to 119 months (median, 53 months). The Kaplan-Meier plot estimated an overall survival rate of 91.6% at 7 years after diagnosis. Among the 12 patients without chemotherapy, 2 children had relapses at 4 and 6 months after diagnosis, respectively. One was cured with PVB chemotherapy. The other patient died with refractory lung metastasis, in spite of intensive multimodality salvage therapy. The Kaplan-Meier plot showed a survival rate of 80% at 7 years and a relapse-free survival rate of 81.8% at 5 years after diagnosis. All children receiving chemotherapy were alive and free from relapse. There was no significant treatment-related toxicity. Our results may suggest that PVB chemotherapy after orchiectomy is an affective and safe regimen for stage I yolk sac tumor of testis in children younger than 2 years. Instead of four courses of PVB as used here, two or three courses could be enough. To elucidate the necessity for chemotherapy and to determine the number of courses of PVB needed (if chemotherapy is given), a randomized study of more cases is warranted.

Prenatal and neonatal intussusception

Intussusception found in the 1st month of life is rare and usually discussed as one entity, neonatal intussusception, but in fact, includes the intussusceptions occurring both prenatally and neonatally, of which the clinical presentations and results are different. Four full-term babies with prenatal intussusception presenting as intestinal atresia (IA) and three premature babies with neonatal intussusception mimicking necrotizing enterocolitis (NEC) are presented. Prenatal intussusception, as one of the causes of IA produces prominent signs of intestinal obstruction immediately after birth. Preoperative evaluation usually fails to yield a definitive diagnosis, but surgery is usually performed in time and is successful. In neonatal intussusception, full-term infants usually have a pathological lead point and the colon is almost always involved. A barium enema is thus useful in diagnosis. Premature babies, on the other hand, rarely have a colonic component, and the clinical features are insidious and similar to NEC. This results in diagnostic confusion that may lead to a dangerous delay in appropriate surgical correction. A high level of suspicion about this condition in cases diagnosed presumptively with NEC is important. Serial abdominal sonograms may be helpful in the early diagnosis of neonatal intussusception.