The role of blood groups, vaccine type and gender in predicting the severity of side effects among university students receiving COVID-19 vaccines.

On March 11th, 2020, the World Health Organization (WHO) declared the coronavirus disease 2019 (COVID-19) a pandemic. To control the pandemic, billions of vaccine doses have been administered worldwide. Predictors of COVID-19 vaccine-related side effects are inconsistently described in the literature. This study aimed to identify the predictors of side effects' severity after COVID-19 vaccination among young adult students at Taif University (TU) in Saudi Arabia. An online, anonymous questionnaire was used. Descriptive statistics were calculated for numerical and categorical variables. Possible correlations with other characteristics were identified using the chi-square test. The study included 760 young adult participants from TU. Pain at the injection site (54.7%), headache (45.0%), lethargy and fatigue (43.3%), and fever (37.5%) were the most frequently reported COVID-19 vaccine-related side effects after the first dose. The most frequent side effects were reported among the 20-25-year-old age group for all doses of all vaccines. Females experienced remarkably more side effects after the second (p < 0.001) and third doses (p = 0.002). Moreover, ABO blood groups significantly correlated with vaccine-related side effects after the second dose (p = 0.020). The participants' general health status correlated with the side effects after the first and second doses (p < 0.001 and 0.022, respectively). The predictors of COVID-19 vaccine-related side effects in young, vaccinated people were blood group B, female gender, vaccine type, and poor health status.

Psychological impacts of COVID-19 pandemic on the university students in Egypt.

University students are at elevated risk for mental health problems. The COVID-19 pandemic and subsequent public health measures taken to combat it burdened the students' life with additional dramatic psychological impacts. The aim of this study was to investigate the psychological impacts that affected the university students in Egypt during the COVID-19 pandemic. An online survey was sent to the Egyptian university students via all means of online communication during the first week of May 2020 by using a non-probability snowball sampling. A survey included a short version Depression Anxiety Stress Scale-21 (DASS-21) and socio-demographic data. Overall, 70.5, 53.6 and 47.8% of Egyptian students had depression, anxiety and stress, respectively. Being a female, having a relative or acquaintance infected with COVID-19, having a preexisting chronic disease and lacking of psychological support from families, community and universities increase the risk of depression, anxiety and stress among Egyptian students. Being a medical student is associated with depression while, spending more time to follow news of COVID-19 pandemic is associated with increased anxiety. Egyptian students experience varying levels of psychological disturbance during COVID-19 pandemic. This study suggests that mental health of the university students should be carefully, monitored during the crisis and the universities should provide psychological-oriented services, adapted to these circumstances to mitigate its emotional impact on the students.

Correction: Mohammed et al. Assessment of Knowledge, Attitude, and Practice towards Tuberculosis among Taif University Students. Healthcare 2023, 11, 2807.

In the original publication [...].

An epidemiological study of cutaneous leishmaniasis in Al-jabal Al-gharbi, Libya.

Cutaneous leishmaniasis (CL) is an endemic parasitic infection in the Mediterranean region, including Libya and its Al-jabal Al-gharbi province. We aimed at studying the occupational relevance as well as other epidemiological aspects of CL. We investigated 140 CL cases who attended at Gharyan outpatient polyclinic during a period of 6 months in 2009. CL infection was clinically diagnosed and confirmed by demonstration of Leishmania parasites on smears from lesions. Our findings showed that males were more affected than females (P=0.04), and people above 10-years were more affected than younger ones (P=0.0001). A significant percent of CL cases belonged to Al-Kawasem subprovince (P=0.0001). Farm-related activities were the most frequent occupations among CL cases (P=0.04). In addition to farm workers, housewives and students are at risk groups since they are engaged at farm activities. Moreover, those who have occupations that require staying outdoors for a part of night, e.g., policemen, are also at risk. Compared to children, adult CL patients had multiple lesions (P=0.001) that were more prevalent in their upper and lower extremities than the face (P=0.0001). We conclude that CL is a major health problem in Al-jabal Al-gharbi province of Libya. The presence of rodents and sandflies makes it a suitable environment for Leishmania to spread in an endemic epidemiological pattern. Being engaged in farming activities or outdoor occupations increases the risk of infection. Various clinical patterns of CL suggest the presence of more than 1 species of Leishmania at Al-jabal Al-gharbi province. We propose that the 2 species responsible for CL in this area are L. major and L. tropica. Further investigations to identify the leishmanial species responsible for CL at Al-jabal Al-gharbi together with adoption of preventive and control programs are needed.

Public perspective toward extended community pharmacy services in sub-national Saudi Arabia: An online cross-sectional study.

BACKGROUND: In many developed countries, the scope of community pharmacy services has extended to include advanced applications. Unlike traditional practices that focus on pharmaceutical sales, extended community pharmacy services (ECPSs) are patient-centred and typically offered by specialised healthcare centres, which improve public health, reduce pressure imposed on healthcare professionals, and rationalise health system expenditures. However, based on the findings of several studies, community pharmacies (CPs) only provide marginalised services. Public reviews are thus crucial to effectively utilise such services. This study explored CPs use among the Saudi public in terms of knowledge, attitudes, and barriers to ECPSs. MATERIALS AND METHODS: We conducted a cross-sectional web-based survey of a non-probability sample between October and December 2021. Numerical and graphical descriptive statistics were employed with an additional analytical assessment using binary logistic regression to determine the association between participant characteristics and the barriers to ECPSs use. RESULTS: A total of 563 individuals participated in this study, approximately 33% of which revealed CPs as the first place they visit for medication concerns. Most individuals were not aware of medication therapy management and health screening services (77% and 68%, respectively). Pharmacy clinics offering private counselling and receiving patient electronic medical records were unknown to the participants (78% and 63%, respectively). A substantial proportion of the cohort considered lack of privacy (58%) and inadequate communication with community pharmacists (56%) as key barriers to the use of ECPSs. Logistic regression analysis revealed that the underdeveloped infrastructure of CPs was significantly associated with almost all factors. CONCLUSION: Most services and facilities were found to be underutilised. Positive public attitudes were associated with concerns regarding privacy and cost of services. Consistent with Saudi Vision 2030, supporting CPs and increasing the public awareness of ECPSs have significant implications on public health.

Assessment of Knowledge, Attitude, and Practice towards Tuberculosis among Taif University Students.

Tuberculosis (TB) remains a significant public health concern worldwide. Given the dense living and interactive nature of university environments, students may be at higher risk. This cross-sectional study assessed tuberculosis-related knowledge, attitudes, and practices (KAP) among students at Taif University (TU) from November 2022 to May 2023. Using a self-administered online questionnaire with 40 items, 1155 students participated. Key demographics: 68.2% females, 96.9% Saudi citizens, 94.5% unmarried, and 87.5% non-smokers. Of the respondents, 26.5% had no knowledge of TB. The TB-related KAP scores among the aware students were 64.9%, 74.8%, and 81%, respectively. Medical college students exhibited significantly higher TB-related knowledge and attitudes than their non-medical peers (p < 0.001). The findings indicate a commendable level of TB-awareness among TU students, but there remains a substantial uninformed segment. Campaigns to enhance TB knowledge among TU students are suggested.

Climatic influence on the reproductive characteristics of Japanese males.

We previously performed a survey of the sperm characteristics of the partners of pregnant women in four cities in Japan. In the present study, we analyzed the sperm characteristics of these subjects and the correlations between these sperm characteristics and climatic changes or Y chromosome haplogroups. Our results showed that more haplogroup D2a1 males than O2b1 males were born in the first half of the year (January to June), whereas more O2b1 males were born in the last half of the year (July to December) (P<0.05). This was agreed and correlated with the seasonal variations in their mean sperm concentrations. The haplogroup C, D* and D2a1 males displayed lower sperm concentrations from March to May, followed by an increase in their sperm concentrations starting in June or July, while the O2b1 males displayed higher sperm concentrations in the first half of the year followed by a sudden decrease from July to August (P<0.05). We hypothesize that the Japanese climate has different effects on the sperm characteristics and reproductive seasonality of males from different lineages; and therefore, has influenced the modern population of Japan.

Correlation between the severity of COVID-19 vaccine-related adverse events and the blood group of the vaccinees in Saudi Arabia: A web-based survey.

Background: Recent epidemiological studies have reported an association between the ABO blood group and the acquisition, symptom severity, and mortality rate of coronavirus disease 2019 (COVID-19). However, the association between the ABO blood group antigens and the type and severity of COVID-19 vaccine-related adverse reactions has not been elucidated. Patients and Methods: We conducted a cross-sectional, questionnaire-based study in Saudi Arabia from February to April 2022. The study cohort included adults who had received or were willing to receive at least two doses of a COVID-19 vaccine of any type. We used Chi-square test to assess the association between the ABO blood groups and vaccine-related adverse reactions. p values of <0.05 were considered significant. Results: Of the 1180 participants, approximately half were aged 18-30 years old, 69.2% were female, and 41.6% reported their blood group as O. The most frequent COVID-19 vaccine-related adverse reactions were fatigue (65%), pain at the injection site (56%), and headache (45.9%). These adverse reactions demonstrated significant correlations with the education level (p = 0.003) and nationality (p = 0.018) of the participants following the first dose, with gender (p < 0.001) following the second dose, and with the general health status (p < 0.001) after all the doses. Remarkably, no correlation was observed between the severity of the vaccine-related adverse reactions and ABO blood groups. Conclusion: Our findings do not support a correlation between the severity of COVID-19 vaccine-related adverse reactions and the ABO blood groups of the vaccinees. The creation of a national database is necessary to account for population differences.

High Seroprevalence of SARS-CoV-2 IgG and RNA among Asymptomatic Blood Donors in Makkah Region, Saudi Arabia.

The gold-standard approach for diagnosing and confirming Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2) infection is reverse transcription-polymerase chain reaction (RT-PCR). This method, however, is inefficient in detecting previous or dormant viral infections. The presence of antigen-specific antibodies is the fingerprint and cardinal sign for diagnosis and determination of exposure to infectious agents including Corona virus disease-2019 (COVID-19). This cross-sectional study examined the presence of SARS-CoV-2 spike-specific immunoglobulin G (IgG) among asymptomatic blood donors in Makkah region. A total of 4368 asymptomatic blood donors were enrolled. They were screened for spike-specific IgG using ELISA and COVID-19 RNA by real-time PCR. COVID-19 IgG was detected among 2248 subjects (51.5%) while COVID-19-RNA was detected among 473 (10.8%) subjects. The IgG frequency was significantly higher among males and non-Saudi residents (p < 0.001 each) with no significant variation in IgG positivity among blood donors with different blood groups. In addition, COVID-19 RNA frequency was significantly higher among donors below 40-years old (p = 0.047, χ2 = 3.95), and non-Saudi residents (p = 0.001, χ2 = 304.5). The COVID-19 IgG levels were significantly higher among the RNA-positive donors (p = 001), and non-Saudi residents (p = 0.041), with no variations with age or blood group (p > 0.05). This study reveals a very high prevalence of COVID-19 IgG and RNA among asymptomatic blood donors in Makkah, Saudi Arabia indicating a high exposure rate of the general population to COVID-19; particularly foreign residents. It sheds light on the spread on COVID-19 among apparently healthy individuals at the beginning of the pandemic and could help in designing various control measures to minimize viral spread.

SRY interacts with ribosomal proteins S7 and L13a in nuclear speckles.

The SRY (sex-determining region on the Y chromosome) is essential for male development; however, the molecular mechanism by which the SRY induces testis development is still unclear. To elucidate the mechanism of testis development, we identified SRY-interacting proteins using a yeast two-hybrid system. We found two ribosomal proteins, RPS7 (ribosomal protein S7) and RPL13a (ribosomal protein L13a) that interact with the HMG (high-mobility group) box domain of SRY. Furthermore, we confirmed the intracellular distributions of RPS7, RPL13a and SRY and found that the three proteins were co-expressed in COS1 cells. SRY, RPS7 and RPL13a were co-localized in nuclear speckles. These findings suggest that SRY plays an important role in activities associated with nuclear speckles via an unknown mechanism.

Prevalence of Gastroesophageal Disease and Associated Risk Factors Among the Population in Al-Qunfudah.

Background and objective Gastroesophageal reflux disease (GERD) is one of the most common gastrointestinal diseases worldwide. It causes an unpleasant effect on patients' lives and may lead to serious complications resulting in a significant burden on healthcare systems. Despite being a common gastrointestinal disease, very few studies have been conducted on the condition in Saudi Arabia; and there has never been a study to estimate the prevalence of GERD in the Al-Qunfudah Governorate. In light of this, we conducted this study with an aim to assess the prevalence of GERD and its associated risk factors among the Al-Qunfudah population. Methods A cross-sectional study was conducted in the Al-Qunfudah Governorate by using an online self-administrated questionnaire that was shared through social media during the first week of January 2021. The questionnaire consisted of a general section on sociodemographic data and a section on the diagnosis of GERD based on the validated gastroesophageal reflux disease questionnaire (GERD-Q). A total of 1,180 eligible participants responded to the questionnaire. Results Nearly one-third (32.9%) of the study participants had GERD based on their reported symptoms and calculated scores (GERD-Q score ≥8). About 14.8% of the participants (175/1,180) reported that they had already been diagnosed with GERD before their participation in our survey. Regarding risk factors of GERD, about 35% reported experiencing psychological stress, 28.3% had a family member diagnosed with GERD, and 18.1% were smokers; 49.4% of the participants had their symptoms aggravated by consuming fatty or fried food and 46.7% by spicy food. One of the factors that helped to relieve GERD symptoms was avoiding symptom-aggravating food, as reported by more than half (50.7%) of the participants. Conclusion The prevalence of GERD in the Al-Qunfudah population is high as the condition has affected one-third of the adult population. Our study confirms that male gender, age of 30 years or above, being overweight or obese, being married, smoking habit, use of non-steroidal anti-inflammatory drugs (NSAIDs), having psychological stress, being asthmatic, or having a family history of GERD are factors that significantly increase the likelihood of developing GERD. The reported risk factors include experiencing psychological stress, a family history of GERD, high BMI, and smoking.

The male-determining gene SRY is a hybrid of DGCR8 and SOX3, and is regulated by the transcription factor CP2.

In mammals, sex is determined by the presence or absence of the Y chromosome that bears a male-dominant sex-determining gene SRY, which switches the differentiation of gonads into male testes. The molecular signaling mechanism turning on the switch, however, has remained unclear for 18 years since the identification of the gene. Here, we describe how this gene emerged and started to work. From amino acid homology, we realized that SRY is a hybrid gene between a portion of the first exon of DiGeorge syndrome critical region gene 8 (DGCR8) and the high-mobility group (HMG) box of SRY box-3 (SOX3) gene. We identified the regulatory sequence in the SRY promotor region by searching for a common motif shared with DGCR8 mRNA. From the motif search between DGCR8 mRNA and the SRY upstream sequence, we found that the transcription factor CP2 (TFCP2) binding motif is present in both. TFCP2 overexpression did not show a significant increase of SRY mRNA expression, and TFCP2 suppression by RNA interference (RNAi) significantly reduced SRY mRNA expression. Furthermore, electrophoretic mobility shift assay (EMSA) demonstrated that TFCP2 acts as a regulator by directly binding to the SRY promoter. We conclude that SRY is a hybrid gene composed of two genes, DGCR8 and SOX3; and TFCP2 is an essential transcription factor for SRY expression regulation.

Proteasome subunits are regulated and expressed in comparable concentrations as a functional cluster.

The proteasome is the main proteolytic enzyme that functions in the ubiquitin-proteasome system. The 26S proteasome has multi-subunit protease complexes consisting of 20S subunits composed of four seven-numbered rings with two outer rings containing alpha subunits and two central rings composed of beta subunits, and 19S caps of 6 ATPase and 11 non-ATPase subunits; however, it is unclear how these subunits are regulated and the 26S proteasomes assembled. To verify whether each subunit's mRNA expression is associated with the mRNA expression of other proteasome subunits, we carried out expression analysis of 34 proteasome subunits mRNA on peripheral blood from 75 subjects. The expression of proteasome subunits mRNA was comparable in each individual of the studied population and the mRNA expression has been investigated in each 20S or 19S proteasome. Our results suggest that each type of subunit is regulated by respectively common factors, and that the 20S and 19S proteasomes are regulated by different systems.

Proteomics and transcriptome approaches to investigate the mechanism of human sex determination.

The SRY gene (sex-determining region on the Y chromosome) was isolated in 1990 and is known as the testis-determining factor on the Y chromosome. The SRY has been considered as a transcription factor since it contains an HMG box, which functions as a DNA-binding domain. However, a direct target for SRY remains to be identified. We have investigated the function of SRY through proteomics and transcriptome approaches, and by using two stable SRY-overexpressing cell lines (SRY1 and SRY2) in NT2/D1 cells derived from human testicular embryonal cell carcinoma. The results of 2-dimensional gel electrophoresis show that SRY overexpression causes a considerable downregulation of many chaperone proteins. SRY also upregulates laminin, which is important for Sertoli cell differentiation. Additionally, transcriptome analysis shows that SRY overexpression upregulates many zinc finger proteins and downregulates cellular growth factors with S or G(2)/M arrest of the cell cycle and inhibition of cellular proliferation.

Effects of lifestyle habits and eating meals together with the family on the prevalence of obesity among school children in Tokushima, Japan: a cross-sectional questionnaire-based survey.

Obesity in children has become a major global public health concern. The prevention of obesity must start from early childhood in order to establish sound lifestyle habits and promote healthy adulthood. In this study, we evaluated factors associated with the prevention of obesity and the development of healthy lifestyle habits in children. A cross-sectional, questionnaire-based survey was performed in elementary and junior high school students in Tokushima Prefecture, Japan, during the summer of 2004. The questionnaire consisted of 30 items such as physique, sleep, eating habits, diet, exercise, free time, and attending after-school lessons. Our study revealed that eating meals as a family every day is associated with a lower rate of obesity as well as getting good lifestyle habits such as eating balanced meals and getting enough sleep. Of the 3,291 students who responded to the questionnaire, 2,688 (81.7%) reported that they eat meals with their family every day. The percentage of students who eat meals with their family every day decreased with increasing school grade, with the lowest percent in the junior high school students. However, the results regarding female junior high school students revealed a marked association between eating meals with the family every day and good lifestyle habits. We recommend that parents and school teaching staff encourage the establishment of sound, healthy lifestyle habits in children from early childhood as an effective measure for the prevention of obesity.

Effect of one session of ER:YAG laser ablation plus topical 5Fluorouracil on the outcome of short-term NB-UVB phototherapy in the treatment of non-segmental vitiligo: a left-right comparative study.

BACKGROUND: NB-UVB phototherapy is a very important modality in treating vitiligo but the treatment course usually exceeds 1 year. Skin ablation with mechanical dermabrasion with 5Fluorouracil (5FU) was introduced to treat vitiligo in 1983. This was modified replacing the mechanical dermabrasion by erbium-YAG (ER:YAG) laser ablation and resulted in better prognosis in periungual vitiligo. PURPOSE: In the present study, we are exploring the effect of the use of ER:YAG laser skin ablation and application of 5FU on the outcome of short-term NB-UVB therapy for patients with non-segmental vitiligo (NSV). METHODS: This study included 50 adult patients with a total of 65-paired symmetrical NSV lesions in different body parts. One side was treated with ER:YAG laser ablation, followed by 5FU application before simultaneous NB-UVB therapy of both sides for a maximum period of 4 months. The outcome was then evaluated both qualitatively and quantitatively. RESULTS: The overall response to therapy was better using the combination therapy. Fifty patients (78.1%) experienced a moderate-marked repigmentation response in the combination group compared with 23.4% in the mono-therapy group. The response was significantly higher when using the combination therapy in different body parts (P value is <0.05), except for feet lesions, which were better but not statistically significant (P value=0.15). Tolerable pain during ablation or at sites of 5FU application was reported in all cases. Transient hyperpigmentation occurred in 30% of cases and 3.1% of lesions healed by a transient slate blue color. Half of the treated periungual lesions showed a temporary tiny brownish spot on nail plates and Köebnerization was not detected in any patient. CONCLUSION: We concluded that prior use of ER:YAG laser skin ablation, followed by 5FU application before NB-UVB phototherapy for vitiligo is a safe and tolerable technique that improves the outcome of short-term NB-UVB therapy and is expected to increase patient compliance.

Dietary Factors Associated with Pancreatic Cancer Risk in Minia, Egypt: Principal Component Analysis

Background: Pancreatic cancer (PC) is a serious and rapidly progressing malignancy. Identifying risk factors including dietary elements is important to develop preventive strategies. This study focused on possible links between diet and PC. Methods: We conducted a case-control study including all PC patients diagnosed at Minia Cancer Center and controls from general population from June 2014 to December 2015. Dietary data were collected directly through personal interviews. Principal component analysis (PCA) was performed to identify dietary groups. The data were analyzed using crude odds ratios (ORs) and multivariable logistic regression with adjusted ORs and 95% confidence intervals (CIs). Results: A total of 75 cases and 149 controls were included in the study. PCA identified six dietary groups, labeled as cereals and grains, vegetables, proteins, dairy products, fruits, and sugars. Bivariate analysis showed that consumption of vegetables, fruits, sugars, and total energy intake were associated with change in PC risk. In multivariable-adjusted models comparing highest versus lowest levels of intake, we observed significant lower odds of PC in association with vegetable intake (OR 0.24; 95% CI, 0.07-0.85, P=0.012) and a higher likelihood with the total energy intake (OR 9.88; 95% CI, 2.56-38.09, P<0.0001). There was also a suggested link between high fruit consumption and reduced odds of PC. Conclusions: The study supports the association between dietary factors and the odds of PC development in Egypt. It was found that higher energy intake is associated with an increase in likelihood of PC, while increased vegetable consumption is associated with a lower odds ratio.

Gene expression profile in squamous cell carcinoma of the urinary bladder using complementary deoxyribonucleic acid microarray.

To date, molecular evidence studies for bladder cancer, using the microarray technology, are focusing on the transitional cell carcinoma, however, similar fingerprinting studies have rarely been performed on the other molecular phenotypes of bladder cancer, squamous cell carcinoma (SCC). This study was conducted to monitor the gene expression profiles for bilharzial-related SCC of the bladder to be able to compare its data with transitional cell carcinoma microarray data. A total of 17 paired bilharzial urinary bladder SCC specimens and their corresponding normal urothelium were analyzed using the complementary deoxyribonucleic acid microarray hybridization approach to study the molecular basis of the development of SCC of the urinary bladder. Validation of the microarray results was performed using the Northern blotting technique. After supervised analysis of the microarray data, there was at least a 3-fold difference in the expression between SCC of the bladder and normal urothelium in 82 genes. A total of 38 genes were up-regulated in SCC of the bladder, including matrix degradation-related genes, growth factors, different oncogenes, and immunology related genes. Conversely, 44 genes were down-regulated in SCC of the bladder, including integrins, laminins, cadherins, nonmetastatic cell 1 (NM23) and apoptosis-related genes. Our findings can explain the aggressive behavior of SCC of the bladder. Such gene profiling studies will add to our understanding of the mechanisms of carcinogenesis, and may also improve our ability to diagnose and treat bladder cancer.

Y chromosomal STRs haplotypes in two populations from Bolivia.

In the present study, we typed our previously reported two microsatellite markers, DXYS241 and DXYS266 together with a basic set of nine Y-STRs (DYS19, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DXYS156Y, DYS413) on Y chromosomes from two Bolivian populations. Unrelated males from communities living at high- (N=59) and low- (N=142) altitude, were studied. Combining the alleles into 11 Y-STRs haplotypes revealed that the high-altitude population is significantly less diverse than the low-altitude population. Haplotype diversities of 0.927+/-0.029 and 0.996+/-0.002 were found within the high-altitude, and the low-altitude populations, respectively. Within the high-altitude population 40 haplotypes were detected, whereas in the low-altitude population 113 haplotypes were found. Only three haplotypes were shared between both populations. Haplotyping-based discrimination using the 11 Y-STRs including our new two microsatellite markers DXYS241 and DXYS266 was shown to be powerful than using the conventional 9 Y-STRs, especially for the low-altitude Bolivian population. This 11 Y-STRs-based haplotyping system shows a very high potential for discrimination and could provide an ideal tool for forensic analysis and population studies. Moreover, this study includes data about two Bolivian populations which were not previously reported, this will help in building a world-wide database for future use in forensic and legal studies.

Differences in gene expression between noninvasive and invasive transitional cell carcinoma of the human bladder using complementary deoxyribonucleic acid microarray: preliminary results.

This study was performed to identify differences in gene expression between superficial noninvasive and invasive transitional cell carcinoma (TCC) of the bladder in human beings. We used complementary deoxyribonucleic acid microarrays containing 14,551 different genes to analyze gene expression among 6 cases of superficial and 6 cases of invasive TCC of the bladder to identify differences in gene expression, which might explain differences in the biology and clinical outcomes of these histologic subtypes of TCC. Quantitative real-time polymerase chain reaction was performed for selected genes to validate the microarray data. Significant up-regulation of 40 genes was associated with cases of superficial noninvasive, but not in invasive, TCC of the urinary bladder. This effect included genes involved in epithelial cell dedifferentiation and keratinization, as well as genes related to cell cycle, cell adhesion, transcription, and apoptosis. Conversely, significant up-regulation of 34 genes was associated with cases of invasive TCC, but not in superficial TCC, including genes related to extracellular matrix degradation, immune responses, cell cycling, and angiogenesis. This study shows the usefulness of complementary deoxyribonucleic acid microarray technology for identifying differences in gene expression among different histotypes of bladder cancer.