A glycolytic metabolite bypasses "two-hit" tumor suppression by BRCA2.

Knudson's "two-hit" paradigm posits that carcinogenesis requires inactivation of both copies of an autosomal tumor suppressor gene. Here, we report that the glycolytic metabolite methylglyoxal (MGO) transiently bypasses Knudson's paradigm by inactivating the breast cancer suppressor protein BRCA2 to elicit a cancer-associated, mutational single-base substitution (SBS) signature in nonmalignant mammary cells or patient-derived organoids. Germline monoallelic BRCA2 mutations predispose to these changes. An analogous SBS signature, again without biallelic BRCA2 inactivation, accompanies MGO accumulation and DNA damage in Kras-driven, Brca2-mutant murine pancreatic cancers and human breast cancers. MGO triggers BRCA2 proteolysis, temporarily disabling BRCA2's tumor suppressive functions in DNA repair and replication, causing functional haploinsufficiency. Intermittent MGO exposure incites episodic SBS mutations without permanent BRCA2 inactivation. Thus, a metabolic mechanism wherein MGO-induced BRCA2 haploinsufficiency transiently bypasses Knudson's two-hit requirement could link glycolysis activation by oncogenes, metabolic disorders, or dietary challenges to mutational signatures implicated in cancer evolution.

Laparoscopic management of intestinal obstruction in a young adult with a virgin abdomen: Unusual presentation of combined vitellointestinal duct remnants: A clinical case report.

Key Clinical Message: In an 18-year-old, Meckel's diverticulum and a rare vitellointestinal fibrous band caused bowel obstruction. Clinicians should be vigilant for such anomalies, especially in young adults with virgin abdomens, as potential sources of intestinal obstruction. Abstract: In this case report, we highlight the rarity of vitellointestinal or omphalomesenteric duct anomalies causing intestinal obstruction in the adult population. The patient, an 18-year-old male, presented to the emergency department with a two-day history of abdominal pain and vomiting. Physical examination revealed mild distension of his virgin abdomen with generalized tenderness. Abdominal X-ray displayed dilated small bowel loops, and a computed tomography scan indicated features consistent with closed-loop bowel obstruction. Diagnostic laparoscopy confirmed a vitellointestinal duct remnant as the cause of the small intestinal obstruction, involving a combined Meckel's diverticulum and vitellointestinal fibrous band. In early fetal development, the vitellointestinal duct communicates between the midgut and the yolk sac, expected to disappear during fetal growth. Failure to obliterate can lead to issues such as intestinal blockage, primarily observed in children, making occurrences in adults, as in this case, infrequent with only a few documented instances. Despite its uncommon occurrence in young adults, healthcare providers should consider the vitellointestinal duct anomalous remnant as a potential source of intestinal obstruction, particularly in individuals with a virgin abdomen. Early detection of intestinal obstruction is imperative for patient survival, facilitating prompt management and minimizing the risk of serious morbidities, ultimately contributing to a better patient outcome.

A transcriptional response to replication stress selectively expands a subset of Brca2-mutant mammary epithelial cells.

Germline BRCA2 mutation carriers frequently develop luminal-like breast cancers, but it remains unclear how BRCA2 mutations affect mammary epithelial subpopulations. Here, we report that monoallelic Brca2mut/WT mammary organoids subjected to replication stress activate a transcriptional response that selectively expands Brca2mut/WT luminal cells lacking hormone receptor expression (HR-). While CyTOF analyses reveal comparable epithelial compositions among wildtype and Brca2mut/WT mammary glands, Brca2mut/WT HR- luminal cells exhibit greater organoid formation and preferentially survive and expand under replication stress. ScRNA-seq analysis corroborates the expansion of HR- luminal cells which express elevated transcript levels of Tetraspanin-8 (Tspan8) and Thrsp, plus pathways implicated in replication stress survival including Type I interferon responses. Notably, CRISPR/Cas9-mediated deletion of Tspan8 or Thrsp prevents Brca2mut/WT HR- luminal cell expansion. Our findings indicate that Brca2mut/WT cells activate a transcriptional response after replication stress that preferentially favours outgrowth of HR- luminal cells through the expression of interferon-responsive and mammary alveolar genes.

Adult appendicitis score versus Alvarado score: A comparative study in the diagnosis of acute appendicitis.

Background: Acute Appendicitis (AA) is the most common abdominal surgical emergency. It requires proper management to decrease mortality and morbidity. Clinical scoring systems for diagnosing AA aimed to decrease the use of radiological scans and the rate of negative appendectomies (NA). We aim to assess the adult appendicitis score (AAS) in the diagnosis prediction of AA. Method: A retrospective study with 1303 cases of AA is performed. We compared the correlation of AAS and Alvarado scores to postoperative histopathology. Specificity, sensitivity, Positive Predictive Value (PPV), and Negative Predictive Value (NPV) were assessed. ROC was used. Results: AAS risk stratification was applied to the study population. Group I for a low probability, and groups II and III for an intermediate and high probability of AA. We found that 159 patients were matched in group I, 505, and 639 were in groups II and III of AAS, respectively. The correlation between Alvarado and AAS with HP was significant. AAS ≥ 16 presented sensitivity and specificity of 50 % and 75.47 %, respectively, with PPV of 97.96 % and NPV of 6.02 %, with an accuracy of 51.04 %. Regarding AAS ≥ 11, the sensitivity was 88.96 %, specificity was 39.62 %, PPV was 97.2 %, NPV was 13.21 %, and accuracy was 86.95 %. Conclusion: AAS is relatively more accurate than Alvarado's score, especially in selecting a safe candidate for discharge from an emergency. In addition, AAS is found to decrease the need for radiological images and NA rate more than Alvarado.

Uncommon presentation of complicated internal hernia through the appendices epiploicae ring of adhesion: a clinical case study.

Background: Internal hernias are infrequent, yet serious, medical conditions with potentially severe consequences. An internal hernia resulting from an Appendices epiploicae (AE) ring is an especially rare cause, with a mere nine documented instances worldwide. Case report: This report presents the case of a 58-year-old male who suffered from an internal hernia originating from an AE ring. The condition led to a gangrenous small bowel, which was treated by laparotomy and resection of the affected segment, followed by primary anastomosis. The post-operative recovery was favorable. Conclusion: Internal hernias, although rare, warrant immediate attention and early intervention to preclude detrimental outcomes, as illustrated in this particular case.

Current strategies with implementation of three-dimensional cell culture: the challenge of quantification.

From growing cells in spheroids to arranging them on complex engineered scaffolds, three-dimensional cell culture protocols are rapidly expanding and diversifying. While these systems may often improve the physiological relevance of cell culture models, they come with technical challenges, as many of the analytical methods used to characterize traditional two-dimensional (2D) cells must be modified or replaced to be effective. Here we review the advantages and limitations of quantification methods based either on biochemical measurements or microscopy imaging. We focus on the most basic of parameters that one may want to measure, the number of cells. Precise determination of this number is essential for many analytical techniques where measured quantities are only meaningful when normalized to the number of cells (e.g. cytochrome p450 enzyme activity). Thus, accurate measurement of cell number is often a prerequisite to allowing comparisons across different conditions (culturing conditions or drug and treatment screening) or between cells in different spatial states. We note that this issue is often neglected in the literature with little or no information given regarding how normalization was performed, we highlight the pitfalls and complications of quantification and call for more accurate reporting to improve reproducibility.

BRCA2 deficiency reveals that oxidative stress impairs RNaseH1 function to cripple mitochondrial DNA maintenance.

Oxidative stress is a ubiquitous cellular challenge implicated in aging, neurodegeneration, and cancer. By studying pathogenic mutations in the tumor suppressor BRCA2, we identify a general mechanism by which oxidative stress restricts mitochondrial (mt)DNA replication. BRCA2 inactivation induces R-loop accumulation in the mtDNA regulatory region and diminishes mtDNA replication initiation. In BRCA2-deficient cells, intracellular reactive oxygen species (ROS) are elevated, and ROS scavengers suppress the mtDNA defects. Conversely, wild-type cells exposed to oxidative stress by pharmacologic or genetic manipulation phenocopy these defects. Mechanistically, we find that 8-oxoguanine accumulation in mtDNA caused by oxidative stress suffices to impair recruitment of the mitochondrial enzyme RNaseH1 to sites of R-loop accrual, restricting mtDNA replication initiation. Thus, oxidative stress impairs RNaseH1 function to cripple mtDNA maintenance. Our findings highlight a molecular mechanism that links oxidative stress to mitochondrial dysfunction and is elicited by the inactivation of genes implicated in neurodegeneration and cancer.

High-throughput surface marker screen on primary human breast tissues reveals further cellular heterogeneity.

BACKGROUND: Normal human breast tissues are a heterogeneous mix of epithelial and stromal subtypes in different cell states. Delineating the spectrum of cellular heterogeneity will provide new insights into normal cellular properties within the breast tissue that might become dysregulated in the initial stages of cancer. Investigation of surface marker expression provides a valuable approach to resolve complex cell populations. However, the majority of cell surface maker expression of primary breast cells have not been investigated. METHODS: To determine the differences in expression of a range of uninvestigated cell surface markers between the normal breast cell subpopulations, primary human breast cells were analysed using high-throughput flow cytometry for the expression of 242 cell surface proteins in conjunction with EpCAM/CD49f staining. RESULTS: We identified 35 surface marker proteins expressed on normal breast epithelial and/or stromal subpopulations that were previously unreported. We also show multiple markers were equally expressed in all cell populations (e.g. CD9, CD59, CD164) while other surface markers were confirmed to be enriched in different cell lineages: CD24, CD227 and CD340 in the luminal compartment, CD10 and CD90 in the basal population, and CD34 and CD140b on stromal cells. CONCLUSIONS: Our dataset of CD marker expression in the normal breast provides better definition for breast cellular heterogeneity.

Time-resolved single-cell analysis of Brca1 associated mammary tumourigenesis reveals aberrant differentiation of luminal progenitors.

It is unclear how genetic aberrations impact the state of nascent tumour cells and their microenvironment. BRCA1 driven triple negative breast cancer (TNBC) has been shown to arise from luminal progenitors yet little is known about how BRCA1 loss-of-function (LOF) and concomitant mutations affect the luminal progenitor cell state. Here we demonstrate how time-resolved single-cell profiling of genetically engineered mouse models before tumour formation can address this challenge. We found that perturbing Brca1/p53 in luminal progenitors induces aberrant alveolar differentiation pre-malignancy accompanied by pro-tumourigenic changes in the immune compartment. Unlike alveolar differentiation during gestation, this process is cell autonomous and characterised by the dysregulation of transcription factors driving alveologenesis. Based on our data we propose a model where Brca1/p53 LOF inadvertently promotes a differentiation program hardwired in luminal progenitors, highlighting the deterministic role of the cell-of-origin and offering a potential explanation for the tissue specificity of BRCA1 tumours.

Study of Toll-like Receptor 3 Gene Polymorphism as a Novel Risk Factor for HCV-related Hepatocellular Carcinoma in Egypt.

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) is a highly aggressive cancer with few treatment options. Toll-like receptor 3 (TLR3) plays a key role in innate immunity and may affect the development of cancers. This study aimed to investigate the association between TLR3 gene polymorphism and HCV-related hepatocellular carcinoma in Egypt. METHODS: This work was conducted on 70 individuals; fifty HCV cirrhotic patients were included in two groups; with HCC (30 patients) and without HCC (20 patients) compared with a group of 20 apparently healthy controls. All of the studied individuals underwent clinical-laboratory evaluation. TLR3 gene single-nucleotide polymorphism (SNP) (+1234C/T) was tested by polymerase chain reaction- restriction fragment length polymorphism. RESULTS: This study reported that the prevalence of TLR3 +1234TT genotype was significantly increased in cirrhotic patients with HCC than without HCC, while it was not detected at all among the controls. When analyzing the TLR3 SNP +1234C/T with different clinical parameters in HCC patients, there was a significant association between+1234C/T SNP; namely TT genotype and each of the hepatic focal lesionsá¾½ number, size and the patientsá¾½ higher Okuda and BCLC stages. No association could be detected between TLR3 SNP and the age, sex, Child-Pugh grades, MELD score or AFP of the studied HCC cases. CONCLUSION: TLR3 gene SN P +1234C/T could be a novel risk factor for the HCV-related HCC among the Egyptian population.

Hypervascular Nodules and Stiffer Liver are Associated with Recurrence after Microwave Ablation in Patients with Hepatocellular Carcinoma: A Double-Center Analysis.

Background and Aims The aim of this study was to detect the most important risk factors for recurrence after microwave ablation (MWA) of hepatocellular carcinoma (HCC). Methods A total of 92 patients with 110 HCC focal lesions (FLs) underwent MWA therapy. All the patients underwent triphasic CT before and after 1 and 3 months of MWA therapy. Complete ablation and recurrence rates were recorded, and the risk factors associated with recurrence were analyzed. Results Regarding the 110 HCC FLs that were detected pre-MWA, adequate ablation was recorded post-MWA procedure in 88 FLs (80%) and incomplete ablation in 22 FLs (showed residual contrast enhancement). However, there were newly detected lesions (17 FLs). The rate of recurrence was significantly higher in patients with multiple larger (> 4 cm) sized and hypervascular nodules. Diabetics were significantly associated with a higher recurrence rate of HCC. The rate of recurrence was significantly higher in patients with baseline level of serum alfa-fetoprotein (AFP) ≥200 ng/mL. Stiffer liver> 25 kPa had higher incidence for recurrence after ablation. Conclusion Meticulous follow-up is mandatory in diabetic patients, patients with AFP > 200 ng/dL starting value, hypervascular large hepatic FL, and in stiffer liver> 25 kPa, as these patients have higher incidence for recurrence after ablation.

Effects of gamma-irradiation on antibiotic resistance and diagnostic molecular markers of methicillin-resistant Staphylococcus aureus in Egyptian cancer patients.

Purpose: This in-vitro study aimed to assess in 120 [40 community-acquired (CA-MRSA) & 80 hospital-acquired (HA-MRSA)] isolates from cancer patients whether the transmissible staphylococcal cassette chromosome mec (SCCmec) typing, and the Panton-Valentine leukocidin (PVL) virulence genes detection could be employed as tools for molecular diagnostic purposes to distinguish both methicillin-resistant Staphylococcus aureus (MRSA) categories in radiotherapy treated cancer patients.Materials and methods: SCCmec typing was determined by the combination of the type of the cassette chromosome recombinase genes (ccr) gene complex and the class of the methicillin resistance (mec) gene complex. Besides, a rapid slide latex agglutination test (LAT) and antibiotic resistance spectrum determination before and after irradiation were performed.Results: In the strict sense, with the effect of irradiation; the presence of SCCmec subtypes IVa (22.5% vs. 10.0%), b (47.5% vs. 25.0%), & d (7.5 vs. 2.5%) or type V (15.0% vs. 7.5%) genetic elements and PVL genes (p < .001) were not proved as a signature for CA-MRSA. While, the larger SCCmec types II, and III elements were not detected in 14, and 19 from the 38, and 36 typed HA-MRSA isolates (p < .001), respectively. Remarkable effects on class A & class B mec gene complex and type2, type 3 & type 5 ccr gene complex and an increase in agglutination reaction strength in response to gamma irradiation external stimulus were observed.Conclusions: Different heterogeneous genetic composition with upregulation mecA gene expression was detected after irradiation in the HA- MRSA studied population. CA-MRSA showed remarkable ability to acquire multi-antibiotic resistance after irradiation and propose a novel paradigm for future chemotherapy against the multi-resistant pathogens whose proliferation especially among immunocompromised cancer patients is on the increase.

Natural outer membrane permeabilizers boost antibiotic action against irradiated resistant bacteria.

BACKGROUND: This study sought to develop new strategies for reverting the resistance of pathogenic Gram-negative bacilli by a combination of conventional antibiotics, potent permeabilizers and natural beta lactamase inhibitors enhancing the activity of various antibiotics. METHODS: The antibiotic susceptibility in the presence of natural non-antibacterial tested concentrations of phytochemicals (permeabilizers and natural beta lactamase inhibitors) was performed by disk diffusion and susceptibility assays. Thymol and gallic acid were the most potent permeabilizers and facilitated the passage of the antibiotics through the outer membrane, as evidenced by their ability to cause LPS release, sensitize bacteria to SDS and Triton X-100. RESULTS: The combination of permeabilizers and natural beta lactamase inhibitors (quercetin and epigallocatechin gallate) with antibiotics induced greater susceptibility of resistant isolates compared to antibiotic treatment with beta lactamase inhibitors alone. Pronounced effects were detected with 24.4 Gy in vitro gamma irradiation on permeability barrier, beta lactamase activity, and outer membrane protein profiles of the tested isolates. CONCLUSIONS: The synergistic effects of the studied natural phytochemicals and antibiotics leads to new clinical choices via outer membrane destabilization (permeabilizers) and/or inactivation of the beta lactamase enzyme, which enables the use of older, more cost-effective antibiotics against resistant strains.

Identifying the murine mammary cell target of metformin exposure.

The heterogeneity of breast cancer makes current therapies challenging. Metformin, the anti-diabetic drug, has shown promising anti-cancer activities in epidemiological studies and breast cancer models. Yet, how metformin alters the normal adult breast tissue remains elusive. We demonstrate metformin intake at a clinically relevant dose impacts the hormone receptor positive (HR+) luminal cells in the normal murine mammary gland. Metformin decreases total cell number, progenitor capacity and specifically reduces DNA damage in normal HR+ luminal cells, decreases oxygen consumption rate and increases cell cycle length of luminal cells. HR+ luminal cells demonstrate the lowest levels of mitochondrial respiration and capacity to handle oxidative stress compared to the other fractions, suggesting their intrinsic susceptibility to long-term metformin exposure. Uncovering HR+ luminal cells in the normal mammary gland as the major cell target of metformin exposure could identify patients that would most benefit from repurposing this anti-diabetic drug for cancer prevention/therapy purposes.

Androgen Receptor Signalling Promotes a Luminal Phenotype in Mammary Epithelial Cells.

Androgens influence mammary gland development but the specific role of the androgen receptor (AR) in mammary function is largely unknown. We identified cell subsets that express AR in vivo and determined the effect of AR activation and transgenic AR inhibition on sub-populations of the normal mouse mammary epithelium by flow cytometry and immunohistochemistry. Immunolocalisation of AR with markers of lineage identity was also performed in human breast tissues. AR activation in vivo significantly decreased the proportion of basal cells, and caused an accumulation of cells that expressed a basal cell marker but exhibited morphological features of luminal identity. Conversely, in AR null mice the proportion of basal mammary epithelial cells was significantly increased. Inhibition of AR increased basal but not luminal progenitor cell activity in vitro. A small population of AR-positive cells in a basal-to-luminal phenotype transition was also evident in human breast lobules. Collectively, these data support a role for AR in promoting a luminal phenotype in mammary epithelial cells.

Proliferative heterogeneity of murine epithelial cells in the adult mammary gland.

Breast cancer is the most common cancer in females. The number of years menstruating and length of an individual menstrual cycle have been implicated in increased breast cancer risk. At present, the proliferative changes within an individual reproductive cycle or variations in the estrous cycle in the normal mammary gland are poorly understood. Here we use Fucci2 reporter mice to demonstrate actively proliferating mammary epithelial cells have shorter G1 lengths, whereas more differentiated/non-proliferating cells have extended G1 lengths. We find that cells enter into the cell cycle mainly during diestrus, yet the expansion is erratic and does not take place every reproductive cycle. Single cell expression analyses feature expected proliferation markers (Birc5, Top2a), while HR+ luminal cells exhibit fluctuations of key differentiation genes (ER, Gata3) during the cell cycle. We highlight the proliferative heterogeneity occurring within the normal mammary gland during a single-estrous cycle, indicating that the mammary gland undergoes continual dynamic proliferative changes.

Mammary molecular portraits reveal lineage-specific features and progenitor cell vulnerabilities.

The mammary epithelium depends on specific lineages and their stem and progenitor function to accommodate hormone-triggered physiological demands in the adult female. Perturbations of these lineages underpin breast cancer risk, yet our understanding of normal mammary cell composition is incomplete. Here, we build a multimodal resource for the adult gland through comprehensive profiling of primary cell epigenomes, transcriptomes, and proteomes. We define systems-level relationships between chromatin-DNA-RNA-protein states, identify lineage-specific DNA methylation of transcription factor binding sites, and pinpoint proteins underlying progesterone responsiveness. Comparative proteomics of estrogen and progesterone receptor-positive and -negative cell populations, extensive target validation, and drug testing lead to discovery of stem and progenitor cell vulnerabilities. Top epigenetic drugs exert cytostatic effects; prevent adult mammary cell expansion, clonogenicity, and mammopoiesis; and deplete stem cell frequency. Select drugs also abrogate human breast progenitor cell activity in normal and high-risk patient samples. This integrative computational and functional study provides fundamental insight into mammary lineage and stem cell biology.

Randomized controlled study of a novel triple nitazoxanide (NTZ)-containing therapeutic regimen versus the traditional regimen for eradication of Helicobacter pylori infection.

BACKGROUND: Helicobacter pylori infection has become more and more resistant to conventional first-line treatment regimens. So, there is a considerable interest in evaluating new antibiotic combinations and regimens. Nitazoxanide is an anti-infective drug with demonstrated activity against protozoa and anaerobic bacteria including H. pylori. This work is designed to evaluate the efficacy and safety of a unique triple nitazoxanide-containing regimen as a treatment regimen in Egyptian patients with H. pylori infection. METHODS: Two hundred and 24 patients with upper gastrointestinal tract (GIT) dyspeptic symptoms in whom H. pylori -induced GIT disease was confirmed were included in the study. They have been randomized to receive either nitazoxanide 500 mg b.i.d., clarithromycin 500 mg b.i.d., and omeprazole 40 mg twice daily for 14 days or metronidazole 500 mg b.i.d., clarithromycin 500 mg b.i.d., and omeprazole 40  mg twice daily for 14 days. Laboratory evaluation for H. pylori antigen within the stool was performed 6 weeks after cessation of H. pylori treatment regimens to assess the response. RESULTS: The response to treatment was significantly higher in group 1 of nitazoxanide treatment regimen than group 2 of traditional treatment regimen. One hundred and six cases (94.6%) of 112 patients who completed the study in group 1 showed complete cure, while only 63 cases (60.6%) of 104 patients who completed the study in group 2 showed the same response according to per-protocol (PP) analysis (P<.001). The regimen was well tolerated by all the patients enrolled in the study. CONCLUSION: Nitazoxanide-containing triple therapy is a promising therapy for the first-line eradication of H. pylori. (ClinicalTrials.gov Identifier: NCT02422706).

Purification of Distinct Subsets of Epithelial Cells from Normal Human Breast Tissue.

The mammary epithelium is composed of a variety of specialized cell types that function in a coordinated fashion to produce and eject milk through multiple cycles of pregnancy. The ability to identify and purify these subsets of cells in order to interrogate their growth and differentiation capacities, as well as to characterize the molecular mechanisms that regulate their behavior, is essential in identifying the processes associated with breast cancer initiation and progression. This methods chapter outlines the step-by-step methods for dissociating human breast reduction specimens to a single cell suspension of viable cells. As well, strategies for purifying four distinct subsets of epithelial cells by using fluorescence-activated cell sorting and protocols for interrogating the growth and differentiation properties of these purified cells at clonal densities in adherent culture are also described.

A 2-week Nitazoxanide-based quadruple treatment as a rescue therapy for Helicobacter pylori eradication: A single center experience.

As there are increasing reports of fluoroquinolone resistance on use as a first- or second-line treatment for Helicobacter pylori (H pylori), we aimed at evaluation of the efficacy and safety of nitazoxanide-based regimen as a rescue regimen in Egyptian patients whose previous traditional treatment for H pylori infection failed.In total, 100 patients from the outpatient clinic of the Tropical medicine department, Tanta University hospital in whom the standard triple therapy (clarithromycin-based triple therapy) failed were enrolled in the study. Nitazoxanide (500 mg bid), levofloxacin (500 mg once daily), omeprazole (40 mg bid), and doxycyclin (100 mg twice daily) were prescribed for 14 days. Eradication was confirmed by stool antigen for H pylori 6 weeks after the end of treatment. Among the patients enrolled in the study, 44% of patients were men and the mean age for the participants in the study was 46.41 ±â€Š8.05, 13% of patients were smokers, and 4% of patients had a previous history of upper gastro-intestinal bleeding. A total of 94 patients (94%) completed the study with excellent compliance. Only 1 patient (1%) discontinued treatment due to intolerable side effects and 5 patients (5%) did not achieve good compliance or were lost during follow up. However, 83 patients had successful eradication of H pylori with total eradication rates 83% (95 % CI 75.7-90.3%) and 88.30% (95 % CI 81.8-94.8%) according to an intention-to-treat and per-protocol analysis, respectively. Adverse events were reported in 21% of patients: abdominal pain (6%), nausea (9%) and constipation (12%), (2%) headache, and (1%) dizziness. A 2-week nitazoxanide-based regimen is an effective and safe rescue therapy in Egyptian patients whose previous standard triple therapy has failed.