Age, Gender, and Liver Enzyme Impact Hospital Stay in COVID-19 Minority Patient with Cancer in the USA: Does Race Matters in the Pandemic?

Patients with cancer are known to have a poor prognosis when infected with SARS-CoV-2 infection. We aimed in this study to assess health outcomes in COVID-19 patients with different cancers in comparison to non-cancer COVID-19 patients from different centers in the United States (US). We evaluated medical records of 1,943 COVID-19 Cancer patients from 3 hospitals admitted between December 2019 to October 2021 and compared them with non-cancer COVID-19 patients. Among 1,943 hospitalized COVID-19 patients, 18.7% (n=364) have an active or previous history of cancer. Among these 364 cancer patients, 222 were African Americans (61.7%) and 121 were Caucasians (33.2%). Cancer patients had significantly longer hospitalization compared to controls (8.24 vs 6.7 days). Overall, Lung cancer is associated with high mortality. Patients with a previous history of cancer were more prone to death (p=0.04) than active cancer patients. In univariate and multivariate analyses, predictors of death among cancer patients were male sex, older age, presence of dyspnea, elevated troponin, elevated AST (0.001) and ALT (0.05), low albumin (p=0.04) and mechanical ventilation (p=0.001). Patients with a previous history of cancer were more prone to death when compared to active cancer COVID-19 patients. Early recognition of cancer COVID-19 patients' death-associated risk factors can help determine appropriate treatment and management plans for better prognosis and outcome.

Is mesalazine treatment effective in the prevention of diverticulitis? A review.

Diverticulitis is the most severe form of Diverticular disease (DD). An effective treatment strategy for its prevention has not yet been defined. This review aimed to provide a viewpoint on the role of mesalazine, also note as 5-aminosalicylic acid (5-ASA), in the prevention of diverticulitis. A systematic electronic search of relevant articles was performed using PubMed, Embase, Scopus, and Cochrane. Randomized controlled trials (RCTs), open trials, and retrospective studies, published between January 1999 and January 2020, were identified. Twelve eligible studies that analyzed primary or secondary outcomes of diverticulitis were included. The population included patients with symptomatic uncomplicated diverticular disease (SUDD), or patients with a history of diverticulitis. All studies compared 5-ASA to placebo, rifaximin, or other treatments. Two studies, including 359 patients, assessed the efficacy of 5-ASA in preventing the first appearance of diverticulitis in patients with SUDD. Of these, one showed that 5-ASA was effective, and one did not. Ten studies, including 2.995 patients, assessed the efficacy of 5-ASA treatment in preventing the recurrence of diverticulitis in patients with a history of diverticulitis. Four studies showed that 5-ASA had a certain degree of efficacy. All four RCTs demonstrated that 5-ASA did not significantly reduce the rate of diverticulitis recurrence. In a retrospective trial, 5-ASA was less effective than rifaximin in preventing diverticulitis recurrence. In an open trial, there was no difference between 5-ASA and probiotic treatment. Overall, there is currently conflicting evidence regarding the efficacy of 5-ASA treatment in the prevention of diverticulitis and further RCTs are needed.

HER-2/neu and E-cadherin Expression and Microsatellite Instability in Gastric Dysplasia.

BACKGROUND Gastric dysplasia (GD) is a precursor lesion of gastric adenocarcinoma. Intestinal type gastric carcinoma commonly shows microsatellite instability (MSI) and the diffuse type is associated with down regulation of E-cadherin. HER-2/neu is over-expressed in some cases of gastric cancer. In this study, MSI and expression rates of HER-2/neu and E-cadherin in GD were evaluated. METHODS Paraffin blocks of 21 cases of low grade dysplasia (LD), 11 cases of high grade dysplasia (HD) and 25 cases of indefinite for dysplasia (ID) were collected. After deparaffinization and antigen retrieval, the sections were incubated with antibodies against E-cadherin, hMLH1, hMSH2 and HER-2/neu. The streptavidin-biotin complex method was used followed by peroxidase enzyme development with diaminobenzidine. RESULTS HER-2/neu was positive in six cases of HD (50%), four LD (21%) and two ID (9%). E-cadherin was absent in two cases of LD and showed normal expression in all HD and ID cases. hMLH1 expression was absent or markedly decreased only in the zones of dysplasia in HD (3/11), LD (3/21) and ID (4/25). Absence or diminished expression of hMSH2 was seen in HD (3/11), LD (2/21) and ID (3/25) cases. HER-2/neu expression showed close association with diminished expression of hMLH1 or hMSH2 (p < 0.05). CONCLUSION Stepwise increase in the expression rate of HER-2/neu was seen in ID, LD and HD cases implying its role in cancer evolution. The absence of hMLH1 and hMSH2 in GD may predispose individuals to over-expression of other oncogenes such as HER-2/neu. Abnormal expression of E-cadherin is not a frequent finding in GD.

Folate status and risk of colorectal polyps in African Americans.

Dietary folate status appears to influence risk for colorectal cancer possibly by alterations in DNA methylation and nucleotide precursor pools. Polymorphisms (677C-->T and 1298A-->C) in methylenetetrahydrofolate reductase (MTHFR), a key enzyme in folate metabolism, determines enzyme activity. The frequency of polymorphisms in the gene varies extensively in different populations. We sought to determine the association between folate status, folate metabolism, DNA methylation, tobacco, alcohol consumption, and the risk of colorectal adenomas in African Americans. Among 58 patients who underwent a clinically indicated colonoscopy, 23 patients with histology confirmed colorectal polyps and 35 patients without were recruited for a case-control study. Blood samples were collected from fasting patients for determination of serum and red blood cell (RBC) folate, homocysteine, vitamin B(12), and methylation status. Polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) technique was performed to identify the MTHFR 677 C-->T polymorphism and specific PCR was used to analyze adenomatous polyposis coli (APC) gene-promoter sequence methylation. Among 23 cases, 49 polyps (adenomatous, n = 41 and hyperplastic, n= 8) were identified. Twenty-eight (57%) of the polyps were on the left side and 21 (42%) were on the right side of the colon. There was no association between the presence of colon polyps and levels of folate (serum, RBC), vitamin B(12), or homocysteine. Forty-eight individuals (84%) were homozygous for 677 CC. Of these individuals, 18 (37.5%) had >/=1 colorectal polyps, whereas 30 (62.5%) had no polyps. Nine individuals were heterozygous for 677 CT, and 4 (44%) of these individuals had colon polyps. Eighty-eight percent of the APC gene-promoter sequences tested using peripheral blood DNA from patients were unmethylated. Among the individuals who showed APC methylation, 66% had polyps; 33% were polyp free using their blood DNA. There was highly significant association between smoking and alcohol consumption with the presence of a colon polyp (P= .0006 and P= .05, respectively). In conclusion, the lack of the 677 TT may be a significant risk factor for colon neoplasm in the African-American population. Smoking and alcohol consumption were found to be risk factors for colon polyps. APC gene-promoter sequence methylation found in peripheral blood may be an indicator of risk for polyp formation and an important screening tool.

Bax translocation and mitochondrial fragmentation induced by Helicobacter pylori.

BACKGROUND AND AIMS: Previous in vitro and in vivo studies have revealed an association between Helicobacter pylori infection and apoptosis in gastric epithelial cells. Although involvement of the Bcl-2 family of proteins as well as cytochrome c release has been demonstrated in H pylori induced cell death, the exact role of the mitochondria during this type of programmed cell death has not been fully elucidated. Therefore, we sought to determine whether or not Bax translocation and mitochondrial fragmentation occur on exposure of gastric epithelial cells to H pylori, resulting in cell death. METHODS: Experiments were performed with human gastric adenocarcinoma (AGS) cells, AGS cells transfected with the HPV-E6 gene (which inactivates p53 function), AGS-neo cells (transfected with the backbone construct), mouse embryonic fibroblasts (MEFs), and p19(ARF) null (ARF(-/-)) MEFs. Cells were incubated with a cag positive H pylori strain for up to 24 hours, lysed, and cytoplasmic and mitochondrial membrane fractions were analysed by western blot for Bax translocation. RESULTS: Bax translocation was detected in AGS, AGS-neo, and normal MEF cells after exposure to H pylori for three hours, but not in ARF(-/-) MEFs cells. Translocation of Bax after H pylori incubation was also detected in AGS-E6 cells (inactive p53 gene) but to a lesser degree than in AGS-neo cells. In parallel studies, the mitochondrial morphology of living cells infected with H pylori was assessed by confocal microscopy. Mitochondrial fragmentation was detectable after 10 hours of H pylori incubation with AGS cells and after seven hours with MEF cells. In wild-type MEFs, mitochondrial fragmentation was significantly increased in comparison with ARF null MEFs (43% v 10.4%, respectively). Furthermore, mitochondrial depolarisation and caspase-3 activity were initiated within four hours in cells incubated with H pylori, and these events were inhibited by forced expression of Bcl-2. CONCLUSIONS: These data suggest that during H pylori induced apoptosis, Bax translocates to the mitochondria which subsequently undergo depolarisation and profound fragmentation. Functional ARF and p53 proteins may play an important role in H pylori induced mitochondrial modification.

Promoter methylation regulates Helicobacter pylori-stimulated cyclooxygenase-2 expression in gastric epithelial cells.

Cyclooxygenase (COX)-2, the inducible form of the rate-limiting enzyme for prostaglandin synthesis, is up-regulated in gastrointestinal cancers and is a key mediator of epithelial cell growth. Helicobacter pylori is causally linked to gastric cancer. In H. pylori gastritis, COX-2 expression localizes to the subepithelial region, with variable levels in the epithelium. In contrast, in gastric cancer, COX-2 strongly predominates in the epithelium, suggesting that the transition to consistent epithelial COX-2 overexpression may be a critical molecular event in gastric carcinogenesis. Because aberrant promoter methylation inhibits expression of a variety of genes in gastrointestinal cancers, we sought to determine whether methylation of the COX-2 promoter could regulate the response to H. pylori in gastric epithelial cells. We assessed COX-2 expression and promoter methylation status in six gastric epithelial cell lines. In all four of the cell lines that exhibited basal expression of COX-2 and a significant increase in expression in response to H. pylori, the COX-2 promoter was unmethylated, whereas in the two cell lines that did not express COX-2, the COX-2 promoter was methylated. Treatment of COX-2-methylated cells with the demethylating agent 5-azacytidine had a modest effect on COX-2 expression, but when 5-azacytidine-treated cells were subsequently stimulated with H. pylori, there was a significant, 5-10-fold enhancement of both COX-2 mRNA and protein expression and release of the COX-2 product, prostaglandin E2. In contrast, in COX-2-expressing cell lines that were unmethylated at the COX-2 promoter, 5-azacytidine had no effect on H. pylori-stimulated COX-2 expression. These findings suggest that loss of COX-2 methylation may facilitate COX-2 expression and promote gastric carcinogenesis associated with H. pylori infection.

Influence of Helicobacter pylori on reactive oxygen-induced gastric epithelial cell injury.

Risk factors for gastric cancer are receiving renewed attention in light of the recent positive association of Helicobacter pylori infection with gastric cancer. The effect of H.pylori on the balance between oxidants and antioxidants in the stomach is not well known. In this study, we investigated if exposure of gastric cells to H. pylori increases oxidant-associated gastric epithelial cell injury. A human gastric epithelial cell line (AGS) was grown on 96-well clusters, then exposed overnight to either live H.pylori (four cagA(+) and four cagA(-)) or broth culture supernatant from an isogenic H.pylori cagA(+) strain with and without vacA activity. Incubation of AGS cells with cagA(+) and cagA(-) H.pylori strains before exposure to reactive oxygen species (ROS) reduced cell viability on average to 73.7% and 39.5% of controls, respectively. The percent viability of cells exposed to ROS after incubation with control broth, vacA(-) broth and vacA(+) broth was 97.7%, 70.5% and 63.5%, respectively. Experiments were then performed to evaluate the effects of H.pylori exposure on the activities of ROS-scavenging enzymes [catalase, glutathione peroxidase and superoxide dismutase (SOD)] and formation of 8-hydroxy-2-deoxyguanosine (8-OH-dG) adducts in AGS cells. Overnight exposure to cagA(-) strains reduced catalase activity by 42%; in contrast, exposure to cagA(+) H.pylori strains increased catalase activity by 51%. Glutathione peroxidase activity increased with exposure to both cagA(-) and cagA(+) strains by 95% and 240%, respectively. Total SOD activity increased 156% after exposure to cagA(+) strains and was marginally increased (52%) with exposure to cagA(-) strains. CuZn-SOD protein levels, assayed by enzyme-linked immunosorbent assay, were not significantly altered by exposure to H.pylori strains; however, Mn-SOD concentrations were significantly increased (P: < 0.02) after exposure to both cagA(-) and cagA(+) H.pylori strains. Exposure of AGS cells to cagA(+) and cagA(-) H.pylori was associated with, on average, 44.5 and 99.0 8-OH-dG/10(6) dG, respectively. The increase in catalase, glutathione peroxidase and SOD activity is associated with fewer 8-OH-dG DNA adducts and reduced susceptibility of AGS cells to lethal injury from ROS after exposure to cagA(+) H.pylori strains when compared with exposure to cagA(-) H.pylori strains. Alteration in the activity of ROS-scavenging enzymes by the presence of H. pylori may in part be responsible for the increased risk of gastric cancer in persons infected with H.pylori.

Helicobacter pylori inhibits gastric cell cycle progression.

Helicobacter pylori infection of the gastric mucosa is associated with changes in gastric epithelial cell proliferation. In vitro studies have shown that exposure to H. pylori inhibits proliferation of gastric cells. This study sought to investigate the cell cycle progression of gastric epithelial cell lines in the presence and absence of H. pylori. Unsynchronized and synchronized gastric epithelial cell lines AGS and KatoIII were exposed to H. pylori over a 24-h period. Cell cycle progression was determined by flow cytometry using propidium iodide (PI), and by analysis of cyclin E, p21, and p53 protein expression using Western blots. In the absence of H. pylori 40, 45, and 15% of unsynchronized AGS cells were in G(0)-G(1), S, and G(2)-M phases, respectively, by flow cytometry analysis. When AGS cells were cultured in the presence of H. pylori, the S phase decreased 10% and the G(0)-G(1) phase increased 17% after 24 h compared with the controls. KatoIII cells, which have a deleted p53 gene, showed little or no response to H. pylori. When G1/S synchronized AGS cells were incubated with media containing H. pylori, the G(1) phase increased significantly (25%, P < 0.05) compared with controls after 24 h. In contrast, the control cells were able to pass through S phase. The inhibitory effects of H. pylori on the cell cycle of AGS cells were associated with a significant increase in p53 and p21 expression after 24 h. The expression of cyclin E was downregulated in AGS cells following exposure of AGS cells to H. pylori for 24 h. This study shows that H. pylori-induced growth inhibition in vitro is predominantly at the G(0)-G(1) checkpoint. Our results suggest that p53 may be important in H. pylori-induced cell cycle arrest. These results support a role for cyclin-dependent kinase inhibitors in the G(1) cell cycle arrest exerted by H. pylori and its involvement in changing the regulatory proteins, p53, p21, and cyclin E in the cell cycle.

Effects of Helicobacter pylori on proliferation of gastric epithelial cells in vitro.

OBJECTIVE: H. pylori infection of the gastric mucosa has been associated with an increase in gastric epithelial cell proliferation. However, in vitro adherence of H. pylori to gastric epithelial cells is associated with reduced cell proliferation. Reduction of epithelial cell proliferation may contribute to ulcer formation and delay ulcer healing. The following study was undertaken to elucidate the ability of cagA-positive and -negative strains to impede gastric epithelial cell proliferation. METHODS: A human gastric adenocarcinoma cell line (AGS) was overlaid with either cagA-positive or cagA-negative H. pylori strains suspended in cell culture medium. Proliferation of AGS cells was analyzed by performing direct cell counts and by measuring metabolism of a soluble tetrazolium compound (MTS), after exposure to H. pylori for 24 h. RESULTS: When compared with control cells cultured in medium alone, AGS cell proliferation was reduced by 45.6% and 28.5% due to exposure to cagA-negative and cagA-positive strains, respectively. When bacterial-induced cytotoxicity was assessed by measuring release of lactose dehydrogenase (LDH) into the culture medium, cagA-positive strains were shown to induce significantly more cytotoxicity than cagA-negative strains. CONCLUSIONS: These experiments demonstrate that H. pylori exposure to AGS cells significantly reduces cell proliferation. However, cagA-positive strains that induce more cell injury reduce cell proliferation to a lesser extent than cagA-negative strains. Persistent replication of gastric epithelial cells injured by exposure to cagA-positive strains may be partially responsible for the stronger association with gastric cancer in persons infected with cagA-positive H. pylori strains.

Effectiveness of ranitidine bismuth citrate, clarithromycin, and metronidazole therapy for treating Helicobacter pylori.

OBJECTIVE: There are limited data available from the United States on the effectiveness of ranitidine bismuth citrate (RBC) plus two antibiotics to treat Helicobacter pylori. Therefore, the following study was undertaken to evaluate RBC with two antibiotics, which have been used successfully in combination, to treat H. pylori. METHODS: Adults with and without abdominal symptoms, who had never received H. pylori eradication therapy, were tested for the presence of H. pylori infection either by in-office rapid serology assays or histology. Positive subjects were administered the 13C-urea breath test. Subjects who had a positive urea breath test were then treated with RBC 400 mg b.i.d., clarithromycin 500 mg b.i.d., and metronidazole 500 mg b.i.d. for 10 days. Four to 6 wk after completing antibiotics all subjects were asked to return for a second urea breath test to assess treatment success. RESULTS: Forty-seven of the 50 subjects enrolled into this study completed the antibiotic regimen and returned for a repeat urea breath test. Thirty-seven subjects were negative for H. pylori by urea breath test and 10 were positive, resulting in a 79% eradication rate. Seven subjects (14%) stopped their medication because of side effects. When analysis was performed on the 40 subjects who took > or = 80% of their medication (per-protocol), the eradication rate was 90%. CONCLUSIONS: The combination of RBC with clarithromycin and metronidazole successfully treated H. pylori infection after only 10 days of therapy. The per-protocol eradication rate from this study was similar to that seen with Food and Drug Administration (FDA)-approved regimens. In conclusion, RBC plus clarithromycin and metronidazole should be considered as a first-line treatment regimen for H. pylori infection, and may only need to be taken for a period of 10 days, as opposed to 14 days for FDA-approved regimens.

Development of a two color immunofluorescence stain and immunolocalization method for N-myc and c-myc oncoproteins with a newly generated mouse IgM anti N-myc antibody.

A new mouse monoclonal antibody specific for N-myc oncoprotein was generated and used in combination with an anti-c-myc antibody to develop two color immunofluorescence staining and ultrastructural immunolocalization of N-myc and c-myc in well established (SK-N-SH; CHP 126) and in newly established neuroblastoma (NB) cell lines. Analysis and quantitation of c-myc and N-myc in dually stained cells was done by flow cytometry. Immunolocalization was done by staining with immunogold secondary antibodies and transmission electron microscopy. The results obtained from analysis of 13 newly established NB cell lines revealed, great heterogeneity in the expression of N-myc oncoprotein with 10/13 cell lines over expressing the protein. C-myc oncoprotein was also expressed in all cell lines, however, the level of expression was 4-10-fold lower than the N-myc oncoprotein. Localization studies of c-myc and N-myc oncoproteins on the level of light microscopy and electron microscopy revealed exclusive nuclear localization of c-myc whereas N-myc was localized to the nucleus and to the cytoplasm.

Gene amplification associated with the dominant cob-354 cobalt resistance trait in Dictyostelium discoideum.

A DNA amplification is correlated with the dominant, unstable cob-354 cobalt resistance trait in the cellular slime mold, Dictyostelium discoideum. The amplified DNA is present as about 50 copies of an extrachromosomal element. Cells grown under nonselective conditions in the absence of cobalt ions lose both the cobalt resistance trait and all extrachromosomal copies of the amplified DNA. The amplified DNA is transferrable to new genetic backgrounds by parasexual genetic crosses. These results explain the inability to map the cob-354 trait to a linkage group. The chromosomal origin of the amplified DNA is group III or VI. Thus the resistance trait appears to be independent of the previously known cobalt resistance locus, cobA, which maps to group VII. A developmental defect involving the production of multiply-tipped aggregates that do not complete fruiting body formation also is correlated with the presence of the amplified DNA.

Identification of nuclear proteins that specifically interact with adeno-associated virus type 2 inverted terminal repeat hairpin DNA.

A palindromic hairpin duplex containing the inverted terminal repeat sequence of adeno-associated virus type 2 (AAV) DNA was used as a substrate in gel retardation assays to detect putative proteins that specifically interact with the AAV hairpin DNA structures. Nuclear proteins were detected in extracts prepared from human KB cells coinfected with AAV and adenovirus type 2 that interacted with the hairpin duplex but not in nuclear extracts prepared from uninfected, AAV-infected, or adenovirus type 2-infected KB cells. The binding was specific for the hairpin duplex, since no binding occurred with a double-stranded DNA duplex with the identical nucleotide sequence. Furthermore, in competition experiments, the binding could be reduced with increasing concentrations of the hairpin duplex but not with the double-stranded duplex DNA with the identical nucleotide sequence. S1 nuclease assays revealed that the binding was sensitive to digestion with the enzyme, whereas the protein-bound hairpin duplex was resistant to digestion with S1 nuclease. The nucleotide sequence involved in the protein binding was localized within the inverted terminal repeat of the AAV genome by methylation interference assays. These nuclear proteins may be likely candidates for the pivotal enzyme nickase required for replication or resolution (or both) of single-stranded palindromic hairpin termini of the AAV genome.

Establishment of the nuclear location of Dictyostelium discoideum plasmids.

The nuclear location of the Dictyostelium discoideum plasmids was studied using a biochemical approach based on the presence of plasmid sequences in nucleosomes. This analysis revealed that all four of the known plasmids (Ddp1, Ddp2, Ddp3, Ddp5) are present in chromatin. This evidence establishes that the D. discoideum plasmids are not cytoplasmic but located in the nucleus. D. discoideum is unique among eukaryotes in possessing a group of nonhomologous endogenous plasmids in its nucleus. These plasmids are excellent starting material for construction of nuclear transformation and expression vectors. Such vectors upon transformation into D. discoideum are also present in chromatin as expected for DNA located in the nucleus.