Sunset Yellow dye effects on gut microbiota, intestinal integrity, and the induction of inflammasomopathy with pyroptotic signaling in male Wistar rats

Although concern persists regarding possible adverse effects of consumption of synthetic azo food dyes, the mechanisms of any such effects remain unclear. We have tested the hypothesis that chronic consumption of the food dye Sunset Yellow (SY) perturbs the composition of the gut microbiota and alters gut integrity. Male rats were administered SY orally for 12 weeks. Analysis of fecal samples before and after dye administration demonstrated SY-induced microbiome dysbiosis. SY treatment reduced the abundance of beneficial taxa such as Treponema 2, Anaerobiospirillum, Helicobacter, Rikenellaceae RC9 gut group, and Prevotellaceae UCG-003, while increasing the abundance of the potentially pathogenic microorganisms Prevotella 2 and Oribacterium. Dysbiosis disrupted gut integrity, altering the jejunal adherens junction complex E-cadherin/β-catenin and decreasing Trefoil Factor (TFF)-3. SY administration elevated LPS serum levels, activated the inflammatory inflammasome cascade TLR4/NLRP3/ASC/cleaved-activated caspase-1 to mature IL-1β and IL-18, and activated caspase-11 and gasdermin-N, indicating pyroptosis and increased intestinal permeability. The possibility that consumption of SY by humans could have effects similar to those that we have observed in rats should be examined.

Beneficial Effect of Low Dose Aspirin in Adult Patients with COVID-19: A Retrospective Observational Study in Bangladesh

Presently Coronavirus disease 2019 is a huge human misery that is almost unstoppable with little remedy on board. The disease is predominantly associated with inflammation and thrombosis. Although aspirin exhibits excellent anti-thrombotic and anti-inflammatory properties, it is yet to be explored in treating Covid-19 patients. In this article we want to bring forth its beneficial effect in Covid-19 case management. It is a retrospective observational study. Adult Covid-19 patients either diagnosed with RT-PCR (reverse transcriptase polymerized chain reaction), or categorized as probable cases (as per World Health Organization case definition protocol) by medical doctors were enrolled as participants. Data were collected from doctors' office records for the period ranging from May 2020 to September 2020 in six districts of Bangladesh. Out of 44 participants 42 were eligible (2 children excluded) for the study. Among them 11 participants took low dose aspirin (75mg daily) during the disease process. All participants in aspirin group became cured without complication or death (RR 2.2, 95% CI 1.5-3.2, p<0.001). On the other hand, no aspirin group suffered complications and deaths. The study findings revealed that complications were significantly low among aspirin users. It documented that low dose aspirin is beneficial for Covid-19 patients. Further study is warranted with larger sample size.

Effect of transcranial direct current brain stimulation of the motor cortex on chemotherapy induced nausea and vomiting in female patients with breast cancer

OBJECTIVE

Chemotherapy-induced nausea and vomiting (CINV) is a negative impact associated to chemotherapy and its management still challenging. This study aimed to research the additive impact of single-session tDCS (2 mA) over the motor cortex for 20 minutes before chemotherapy to antiemetic on CINV in female patients suffers from breast cancer who obtained highly emetogenic chemotherapy.

STUDY LAYOUT

Prospective randomized double-blind Sham-controlled study.

SETTING

Academic medical center.

METHOD

Sixty breast cancer patients prepared for chemotherapy treatment were selected and allocated randomly into two equal groups: a real and a sham group; tDCS became implemented over the primary motor area (M1) (2 mA) for 20 minutes. Patients' nausea was measured by cumulative index of nausea and visual analog scale for nausea (VAS-N), and vomiting by cumulative index of episodes of vomiting, and Edmonton symptoms Assessment Scale (ESAS) to assess symptoms like pain, malaise, and sense of well-being. Evaluation was done prestimulation and every 24 h for 72 h after end of infusion of chemotherapy.

RESULTS

Real tDCS group showed reduction of cumulative index of nausea (P < 0.001, F = 50), VAS-N (P < 0.001, F = 52) and for ESAS in malaise score (P < 0.001, F = 37.6) and sense of wellbeing score (P < 0.001, F = 25) than sham group. Six patients (20%) in the real group required rescue antiemtic therapy vs. 14 patients (46.7%) in the Sham group (P < 0.028).

CONCLUSION

Single session of real M1 tDCS could be suggested as an effective adjuvant maneuver in control of CINV in female patients suffers from breast cancer who obtained highly emetogenic chemotherapy.

TRIAL REGISTRATION

Clinical Trials.gov trial registry (identifier: NCT03405324).

Horizontal Transmission of Stress Resistance Genes Shape the Ecology of Beta- and Gamma-Proteobacteria

The transmissible locus of stress tolerance (tLST) is found mainly in beta- and gamma-Proteobacteria and confers tolerance to elevated temperature, pressure, and chlorine. This genomic island, previously referred to as transmissible locus of protein quality control or locus of heat resistance likely originates from an environmental bacterium thriving in extreme habitats, but has been widely transmitted by lateral gene transfer. Although highly conserved, the gene content on the island is subject to evolution and gene products such as small heat shock proteins are present in several functionally distinct sequence variants. A number of these genes are xenologs of core genome genes with the gene products to widen the substrate spectrum and to be highly (complementary) expressed thus their functionality to become dominant over core genome genes. In this review, we will present current knowledge of the function of core tLST genes and discuss current knowledge on selection and counter-selection processes that favor maintenance of the tLST island, with frequent acquisition of gene products involved in cyclic di-GMP signaling, in different habitats from the environment to animals and plants, processed animal and plant products, man-made environments, and subsequently humans.

A recently isolated human commensal Escherichia coli ST10 clone member mediates enhanced thermotolerance and tetrathionate respiration on a P1 phage-derived IncY plasmid

The ubiquitous human commensal Escherichia coli has been well investigated through its model representative E. coli K‐12. In this work, we initially characterized E. coli Fec10, a recently isolated human commensal strain of phylogroup A/sequence type ST10. Compared to E. coli K‐12, the 4.88 Mbp Fec10 genome is characterized by distinct single‐nucleotide polymorphisms and acquisition of genomic islands. In addition, E. coli Fec10 possesses a 155.86 kbp IncY plasmid, a composite element based on phage P1. pFec10 harbours multiple cargo genes such as coding for a tetrathionate reductase and its corresponding regulatory two‐component system. Among the cargo genes is also the Transmissible Locus of Protein Quality Control (TLPQC), which mediates tolerance to lethal temperatures in bacteria. The disaggregase ClpG_GI of TLPQC constitutes a major determinant of the thermotolerance of E. coli Fec10. We confirmed stand‐alone disaggregation activity, but observed distinct biochemical characteristics of ClpG_GI‐Fec10 compared to the nearly identical Pseudomonas aeruginosa ClpG_GI‐SG17M. Furthermore, we noted a unique contribution of ClpG_GI‐Fec10 to the exquisite thermotolerance of E. coli Fec10, suggesting functional differences between both disaggregases in vivo. Detection of thermotolerance in 10% of human commensal E. coli isolates hints to the successful establishment of food‐borne heat‐resistant strains in the human gut.

Sero-prevalence of toxoplasmosis among pregnant women attending an ante-natal clinic at a teaching hospital in Al Kharj, Saudi Arabia

Toxoplasma gondii (T. gondii) is a zoonotic infection that may be transmitted to human beings either by consumption of raw or uncooked meat or by ingesting oocysts. Toxoplasma organisms can cross blood placenta barrier and may result in congenital toxoplasmosis. About 80% of immunocompetent individuals do not show any clinical manifestations and are silent carriers of this disease. Pregnant women especially in highly prevalent areas are recommended to be screened for this disease in order to prevent the potential vertical transmission. To our knowledge no such study has been conducted in this region of Saudi Arabia. This study attempted to carry out two objectives: first, to find out the seroprevalence of T. gondii infection in pregnant women attending prenatal care services in our hospital; second, to find out risk factors associated with T. gondii seroprevalence in our patients. It was carried out in Teaching Hospital in Al-Kharj over a period of one year. All 306 pregnant women attending antenatal clinic were involved in the study. A pretested selfexplanatory questionnaire was filled out by the patients and their sera were collected to be tested for IgG and/or IgM against T. gondii. The results were then statistically analyzed using SPSS software and p-value was calculated using Pearson Chi Square test. Out of the 306 blood samples tested, 99 (32.4%) were seropositive for specific anti T. gondii IgG antibodies and 3(1%) were seropositive for IgM. This show that seroprevalence of T. gondii antibodies was high among pregnant women and the prevalence showed a significant association with age. The study recommends conducting educational programs to raise awareness among women about risk factors and precautions to be taken.

ClpG Provides Increased Heat Resistance by Acting as Superior Disaggregase

Elevation of temperature within and above the physiological limit causes the unfolding and aggregation of cellular proteins, which can ultimately lead to cell death. Bacteria are therefore equipped with Hsp100 disaggregation machines that revert the aggregation process and reactivate proteins otherwise lost by aggregation. In Gram-negative bacteria, two disaggregation systems have been described: the widespread ClpB disaggregase, which requires cooperation with an Hsp70 chaperone, and the standalone ClpG disaggregase. ClpG co-exists with ClpB in selected bacteria and provides superior heat resistance. Here, we compared the activities of both disaggregases towards diverse model substrates aggregated in vitro and in vivo at different temperatures. We show that ClpG exhibits robust activity towards all disordered aggregates, whereas ClpB acts poorly on the protein aggregates formed at very high temperatures. Extreme temperatures are expected not only to cause extended protein unfolding, but also to result in an accelerated formation of protein aggregates with potentially altered chemical and physical parameters, including increased stability. We show that ClpG exerts higher threading forces as compared to ClpB, likely enabling ClpG to process “tight” aggregates formed during severe heat stress. This defines ClpG as a more powerful disaggregase and mechanistically explains how ClpG provides increased heat resistance.

Two FtsH Proteases Contribute to Fitness and Adaptation of Pseudomonas aeruginosa Clone C Strains

Pseudomonas aeruginosa is an environmental bacterium and a nosocomial pathogen with clone C one of the most prevalent clonal groups. The P. aeruginosa clone C specific genomic island PACGI-1 harbors a xenolog of ftsH encoding a functionally diverse membrane-spanning ATP-dependent metalloprotease on the core genome. In the aquatic isolate P. aeruginosa SG17M, the core genome copy ftsH1 significantly affects growth and dominantly mediates a broad range of phenotypes, such as secretion of secondary metabolites, swimming and twitching motility and resistance to aminoglycosides, while the PACGI-1 xenolog ftsH2 backs up the phenotypes in the ftsH1 mutant background. The two proteins, with conserved motifs for disaggregase and protease activity present in FtsH1 and FtsH2, have the ability to form homo- and hetero-oligomers with ftsH2 distinctively expressed in the late stationary phase of growth. However, mainly FtsH1 degrades a major substrate, the heat shock transcription factor RpoH. Pull-down experiments with substrate trap-variants inactive in proteolytic activity indicate both FtsH1 and FtsH2 to interact with the inhibitory protein HflC, while the phenazine biosynthesis protein PhzC was identified as a substrate of FtsH1. In summary, as an exception in P. aeruginosa, clone C harbors two copies of the ftsH metallo-protease, which cumulatively are required for the expression of a diversity of phenotypes.

High frequency of double crossover recombination facilitates genome engineering in Pseudomonas aeruginosa PA14 and clone C strains

Pseudomonas aeruginosa is a key opportunistic human pathogen. An established procedure to replace a target gene is two-step allelic exchange, i.e. selection of single crossover at homologous sequences and subsequent counter selection to induce double crossover for excision of the suicide vector. In this study, we found that certain strains of P. aeruginosa display a high rate of instant double crossover upon introduction of a suicide vector containing an antibiotic resistance cassette flanked by adjacent sequences for gene replacement, making the counter selection step to achieve the second crossover superfluous. Assessment of a limited panel of target genes commonly showed negligible double crossover with a frequency <20 % in the genetic reference strain PAO1, whereas a high double crossover frequency of >70 % was observed for PA14 and clone C strains. Consequently, for certain P. aeruginosa strains replacement of an ORF by a antibiotic resistance cassette can be shortened by directly selecting for double crossover recombination.

Comparative yielding of BACTEC MGIT 960 and GeneXpert MTB/RIF Assay for Rapid Diagnosis of Drug Resistance Tuberculosis from Sputum Specimen

Among communicable disease, tuberculosis is the second leading cause of death worldwide, killing nearly two million people each year. Several diagnostic techniques are currently used to detect mycobacteria in respiratory specimens. Therefore an alternative, rapid and most effective method is required for diagnosis of pulmonary tuberculosis which is relatively more sensitive and specific. A total of 107 sputum samples of suspected TB patients were enrolled attending the National Tuberculosis Reference Laboratory (NTRL), Mohakhali, Dhaka, Bangladesh from July 2014 to July 2015. Liquid culture of 107 sputum samples, yielded 76.63% culture positive and 1.86% contamination was observed. Antibiotic susceptibility test was done for 82 culture positive sputum samples among which 28.04% cases were resistant to both Rifampicin and Isoniazid. GeneXpert assay detected 85.04% M. tuberculosis among which 25.23% were found to be Rifampicin Resistance.

Ancient permafrost staphylococci carry antibiotic resistance genes

Background: Permafrost preserves a variety of viable ancient microorganisms. Some of them can be cultivated after being kept at subzero temperatures for thousands or even millions of years. Objective: To cultivate bacterial strains from permafrost. Design: We isolated and cultivated two bacterial strains from permafrost that was obtained at Mammoth Mountain in Siberia and attributed to the Middle Miocene. Bacterial genomic DNA was sequenced with 40-60× coverage and high-quality contigs were assembled. The first strain was assigned to Staphylococcus warneri species (designated MMP1) and the second one to Staphylococcus hominis species (designated MMP2), based on the classification of 16S ribosomal RNA genes and genomic sequences. Results: Genomic sequence analysis revealed the close relation of the isolated ancient bacteria to the modern bacteria of this species. Moreover, several genes associated with resistance to different groups of antibiotics were found in the S. hominis MMP2 genome. Conclusions: These findings supports a hypothesis that antibiotic resistance has an ancient origin. The enrichment of cultivated bacterial communities with ancient permafrost strains is essential for the analysis of bacterial evolution and antibiotic resistance.

The accuracy and cost-effectiveness of hepatitis C core antigen assay in the monitoring of anti-viral therapy in patients with chronic hepatitis C genotype 4

BACKGROUND

Quantitative hepatitis C (HCV) polymerase chain reaction (qtHCV-PCR), the gold standard for monitoring HCV therapy, is an expensive, time-consuming procedure that requires equipped laboratories and trained personnel.

AIMS

To assess the accuracy and cost-effectiveness of the automated Abbott ARCHITECT HCV Ag assay (Wiesbaden, Germany) in monitoring response to pagylated interferon (PEG-IFN) and ribavirin therapy for chronic HCV genotype 4 (G4).

METHODS

This longitudinal, non-inferiority study compared the efficacy and cost benefit of an All-HCV core antigen assay protocol and a hybrid qtHCV RNA PCR and HCV core Ag assay protocol to the standard All-qtHCV-PCR protocol in chronic HCV G4 patients treated with pegylated interferon (PEG IFN) and ribavirin.

RESULTS

Four hundred and ten patients with chronic hepatitis C genotype 4 met inclusion criteria and were enrolled in the study. The sustained virological response rate (SVR) was 66.34%. The All-HCV core antigen and hybrid monitoring assays resulted in the significant cost savings without compromising performance. A good correlation existed between HCV viral load and HCV core antigen levels (r = 0.944; P < 0.0001). Baseline HCV RNA values <600 IU/mL, baseline HCV core Ag levels <2000 fmol/L, rapid virological response, rapid decline in HCV core antigen were strong predictors of SVR.

CONCLUSION

Hepatitis C core Ag assay is a point-of-care, reproducible, reliable, cost-effective monitoring tool with rapid turnaround time that, which can effectively replace or adjunct to qRT-PCR in monitoring interferon based or interferon-free anti-viral therapy in chronic hepatitis genotype 4 patients in resource-limited countries with a high burden of hepatitis C.

Pseudomyxoma peritonei: A Review

Pseudomyxoma peritonei (PMP) is rare clinical entity characterized by abundant extracellular mucinous material in the peritoneal cavity and tumoural implants on the peritoneal surfaces. The origin of PMP is controversial. It often arises from the goblet cells of large bowel or appendix. There is increase in MUC-2 secreting cells and accumulation of excessive mucin secreted by these cells in the peritoneal cavity. A ruptured appendiceal mucinous adenoma is the most common origin. Low grade ovarian malignancy is often associated. Patient may present with growing abdominal masses associated with abdominal pain, nausea, vomiting, fatigue and weight loss. Ultrasonogram and CT scan of the abdomen have role in diagnosis but diagnosis is often difficult before laparotomy or laparoscopy. Debulking surgery with intraperitoneal hyperthermic chemotherapy is the treatment. DOI: http://dx.doi.org/10.3329/fmcj.v7i2.13523 Faridpur Med. Coll. J. 2012;7(2):88-92

Anthrax: an update

Anthrax is a zoonotic disease caused by Bacillus anthracis. It is potentially fatal and highly contagious disease. Herbivores are the natural host. Human acquire the disease incidentally by contact with infected animal or animal products. In the 18th century an epidemic destroyed approximately half of the sheep in Europe. In 1900 human inhalational anthrax occured sporadically in the United States. In 1979 an outbreak of human anthrax occured in Sverdlovsk of Soviet Union. Anthrax continued to represent a world wide presence. The incidence of the disease has decreased in developed countries as a result of vaccination and improved industrial hygiene. Human anthrax clinically presents in three forms, i.e. cutaneous, gastrointestinal and inhalational. About 95% of human anthrax is cutaneous and 5% is inhalational. Gastrointestinal anthrax is very rare (less than 1%). Inhalational form is used as a biological warefare agent. Penicillin, ciprofloxacin (and other quinolones), doxicyclin, ampicillin, imipenem, clindamycin, clarithromycin, vancomycin, chloramphenicol, rifampicin are effective antimicrobials. Antimicrobial therapy for 60 days is recommended. Human anthrax vaccine is available. Administration of anti-protective antigen (PA) antibody in combination with ciprofloxacin produced 90%-100% survival. The combination of CPG-adjuvanted anthrax vaccine adsorbed (AVA) plus dalbavancin significantly improved survival.

Day-care management of severe and very severe pneumonia, without associated co-morbidities such as severe malnutrition, in an urban health clinic in Dhaka, Bangladesh

BACKGROUND

Management of severe and very severe pneumonia in children relies on hospital-based treatment, but practical barriers often prevent children in areas with the highest rates from receiving hospital care.

OBJECTIVE

To develop and prospectively evaluate a day-care clinic approach, which provided antibiotics, feeding and supportive care during the day with continued care provided by parents at home, as an effective alternative to hospitalisation.

METHODS

Children aged 2-59 months with severe or very severe pneumonia without associated co-morbidities, denied admission to hospital because of lack of beds, were enrolled at Radda Clinic, Dhaka and received antibiotics, feeding and supportive care from 08:00 to 17:00 every day, while mothers were educated on continuation of care at home during the night.

RESULTS

From June 2003 to May 2005, 251 children were enrolled. Severe and very severe pneumonia was present in 189 (75%) and 62 (25%) children, respectively, and 143 (57%) were hypoxaemic with a mean (SD) oxygen saturation of 93 (4)%, which increased to 98 (3)% on oxygen therapy. The mean (SD) day-care period was 7 (2) days. Successful management was possible in 234 children (93% (95% CI 89% to 96%)), but 11 (4.4% (95% CI 2.5% to 7.7%)) had to be referred to hospital, and six (2.4% (95% CI 1.1% to 5.1%)) discontinued treatment. There were no deaths during the day-care study period; however, four children (1.6% (95% CI 0.6% to 4.0%)) died during the 3-month follow-up period, and 11 (4.4% (95% CI 2.5% to 7.7%)) required hospital admission.

CONCLUSION

Severe and very severe pneumonia in children without associated co-morbidities such as severe malnutrition can be successfully managed at day-care clinics.

Day-care management of children with severe malnutrition in an urban health clinic in Dhaka, Bangladesh

Management of severely malnourished children with associated complications relies on hospital-based treatment. Implementation of a standardized protocol at the Dhaka Hospital, ICDDR,B reduced case fatality approximately 50%. We developed and prospectively evaluated a day-care clinic approach that provided antibiotics, micronutrients and feeding during the day with continued care by parents at home at night as an alternative to hospitalization. Severely malnourished children aged 6-23 months denied admission to hospital were enrolled at Radda Clinic, Dhaka and received protocolized management with antibiotics, micronutrients and milk-based diet from 8:00 am to 5:00 pm each day, while mothers were educated on continuation of care at home. They were transitioned to the day-care nutrition rehabilitation (NR) unit of Radda Clinic following resolution of acute illness, received NR diet (Khichuri, halwa and milk-based) daily until children attained 80% weight-for-length. From February 2001 to November 2003, 264 children were enrolled; 52% were boys and 78%, 21% and 1% had marasmus, marasmus-kwashiorkor and kwashiorkor, respectively. Only 13% had severe malnutrition alone while 35% had pneumonia, 35% had diarrhea and 17% had both pneumonia and diarrhea. The mean (SD) duration of acute and NR phases were 8 (4) and 14 (13) days, respectively. Children gained weight [mean (SD) g/kg day] more rapidly during acute 10 (7) than NR phase 6 (5). Successful management was possible in 82% (95% CI 77-86%) children, 12% discontinued treatment and 6% referred to hospitals. Only one child died during NR phase. Severely malnourished children can be successfully managed at existing day-care clinics using a protocolized approach.

Immune modulation by helminthic infections: worms and viral infections

Helminthic infections occur worldwide, especially in developing countries. About one-quarter of the world's population, 1.5 billion, are infected with one or more of the major soil-transmitted helminths, including hookworms, ascarids, and whipworms. Schistosomes infect more than 200 million people worldwide with 600 million at risk in 74 countries. The interaction between helminths and the host's immune system provokes particular immunomodulatory and immunoregulatory mechanisms that ensure their survival in the host for years. However, these changes might impair the immunological response to bystander bacterial, viral, and protozoal pathogens and to vaccination. Modulation of the immune system by infection with helminthic parasites is proposed to reduce the levels of allergic responses and to protect against inflammatory bowel disease. In this review, we summarize the immunological milieu associated with helminthic infections and its impact on viral infections, mainly hepatitis B virus, hepatitis C virus, and human immunodeficiency virus in humans and experimental animals.

Peginterferon {alpha}-2b and ribavirin therapy in chronic hepatitis C genotype 4: impact of treatment duration and viral kinetics on sustained virological response

BACKGROUND

The response rates and duration of peginterferon alpha (PEG-IFN-alpha) and ribavirin combination therapy in chronic hepatitis C genotype 4, the prevalent genotype in the Middle East and Africa, are poorly documented.

AIMS

To compare the efficacy and safety of 24, 36, or 48 weeks of PEG-IFN-alpha-2b and ribavirin therapy in chronic hepatitis C genotype 4.

METHODS

In this prospective, randomised, double blind study, 287 patients with chronic hepatitis C genotype 4 were randomly assigned to PEG-IFN-alpha-2b (1.5 mug/kg) once weekly plus daily ribavirin (1000-1200 mg) for 24 weeks (group A, n = 95), 36 weeks (group B, n = 96), or 48 weeks (group C, n = 96) and followed for 48 weeks after completion of treatment. Early viral kinetics and histopathological evaluation of pre- and post treatment liver biopsies were performed. The primary end point was viral clearance 48 weeks after completion of treatment.

RESULTS

Sustained virological response was achieved in 29%, 66%, and 69% of patients treated with PEG-IFN-alpha-2b and ribavirin for 24, 36, and 48 weeks, respectively, by intention to treat analysis. No statistically significant difference in sustained virological response rates was detected between 36 and 48 weeks of therapy (p = 0.3). Subjects with sustained virological response showed greater antiviral efficacy (epsilon) and rapid viral load decline from baseline to treatment week 4 compared with non-responders and improvement in liver histology. The incidence of adverse events was higher in the group treated for 48 weeks.

CONCLUSION

PEG-IFN-alpha-2b and ribavirin for 36 or 48 weeks was more effective in the treatment of chronic hepatitis C genotype 4 than treatment for 24 weeks. Thirty six week therapy was well tolerated and produced sustained virological and histological response rates similar to the 48 week regimen.

Specific cellular immune response and cytokine patterns in patients coinfected with hepatitis C virus and Schistosoma mansoni

Patients coinfected with hepatitis C virus (HCV) and Schistosoma mansoni show high incidence of viral persistence and accelerated fibrosis. To determine whether immunological mechanisms are responsible for this alteration in the natural history of HCV, the HCV-specific peripheral CD4(+) T cell responses and cytokines were analyzed in patients with chronic hepatitis C monoinfection, S. mansoni monoinfection, or HCV and S. mansoni coinfection. An HCV-specific CD4(+) proliferative response to at least 1 HCV antigen was detected in 73.3% of patients infected with HCV, compared with 8.6% of patients coinfected with HCV and S. mansoni. Stimulation with HCV antigens produced a type 1 cytokine profile in patients infected with HCV alone, compared with a type 2 predominance in patients coinfected with HCV and S. mansoni. In contrast, there was no difference in response to schistosomal antigens in patients infected with S. mansoni alone, compared with those coinfected with HCV and S. mansoni. These findings suggest that the inability to generate an HCV-specific CD4(+)/Th1 T cell response plays a role in the persistence and severity of HCV infection in patients with S. mansoni coinfection.

Acute hepatitis C without and with schistosomiasis: correlation with hepatitis C-specific CD4(+) T-cell and cytokine response

BACKGROUND & AIMS

Immune responses during the first few months of acute hepatitis C virus (HCV) infection seem crucial for viral control, but the relationship of these responses to natural history is poorly characterized.

METHODS

This prospective study investigated the HCV-specific CD4(+) and cytokine responses in patients with acute HCV hepatitis with or without Schistosoma mansoni coinfection, a parasitic infection with T helper (Th) 2 immune bias. HCV-specific CD4(+) proliferative responses and cytokine production in peripheral blood mononuclear cells were correlated with liver biopsy results at 6 months and at the end of follow-up.

RESULTS

Whereas 5 of 15 patients with HCV alone recovered from acute HCV, all (17 of 17) patients with S. mansoni coinfection progressed to histologically proven chronic hepatitis. Coinfected patients had either absent or transient weak HCV-specific CD4(+) responses with Th0/Th2 cytokine production. The magnitude of the HCV-specific CD4(+) response at week 12 was inversely correlated with the fibrosis progression rate in chronically infected patients.

CONCLUSIONS

Patients with acute hepatitis C and schistosomiasis coinfection cannot clear viremia and show rapid progression once chronic infection is established. This rapid progression is associated with a strong Th2 response in peripheral immune responses, suggesting that early development of vigorous Th1 responses not only facilitates clearance but delays disease progression.

Epidemiology of enterotoxigenic Escherichia coli diarrhea in a pediatric cohort in a periurban area of lower Egypt

Enterotoxigenic Escherichia coli (ETEC) are diverse pathogens that express heat-labile (LT) and/or heat-stable (ST) enterotoxins, yet little is known about whether epidemiologic patterns of pediatric ETEC diarrhea vary by the expressed ETEC toxin phenotype. In total, 242 Egyptian children aged <3 years were prospectively followed in 1993-1995. ETEC episodes were detected during twice-weekly home visits, and asymptomatic ETEC excretion was identified from monthly cross-sectional surveys. ETEC episodes were 0.6 per child-year. ST-only ETEC was 2.6 times (P<.001) more common in warmer than cooler months, while LT-only ETEC showed no seasonal variation. Ownership of a household sanitary latrine, but not breast-feeding, was associated with a lower risk of both enterotoxin phenotypes. Coexpression of a colonization factor by LT- or ST-only ETEC strengthened the association with diarrhea. These findings indicate that the epidemiologic patterns of LT-only and ST-only ETEC are not identical and that disease interventions should include improved household sanitation.

Colorectal cancer in Egyptian patients under 40 years of age

Although colorectal cancer is not a common cancer in Egypt, the age distribution of the disease shows that a high proportion occurs in children and adults under 40 years of age. We reviewed the records of 1,608 colorectal cancer patients treated in 4 cancer hospitals in Egypt during a period of 3 to 10 years. The hospitals in which about 85% of all colorectal cancer cases in Egypt were seen included Egypt's 2 major cancer centers, The National Cancer Institute (NCI) in Cairo and Tanta Cancer Center (TCC) in the mid-Nile Delta region, and 2 major university hospitals, Assiut University in South Egypt and Ain Shams University in Cairo. Our review showed that patients younger than 40 years represented 35.6% of all patients in the 4 cancer hospitals, and that these rates were similar among the hospitals and for the years reviewed. The male-to-female ratio increased from 1.0 to 1.7 for the age groups ranging from 0-9 and 30-39 years, and increased from 1.0 to 1.5 for the age groups ranging from 40-49 to over 60 years. More than half of all the patients had rectal tumors, and about 90% of the cancers were adenocarcinomas; 30.6% of patients younger than 40 years, compared with 13.8% of older patients, had mucin-producing tumors. This study confirmed the occurrence of a high colorectal cancer rate in young Egyptians, and it opens the door to future epidemiologic studies to identify causes and risk factors of this disease pattern in Egypt.

Parasitological and bacteriological studies in recurrent diarrhoea in patients with chronic liver diseases

Sixty patients with chronic liver disease complaining of persistent or recurrent diarrhoea where studied. The stools were examined by direct smear, formol ether concentration method and modified Ziehl Neelsen technique for Cryptosporidium in addition to stool cultures for enteric pathogenic bacteria as Salmonella, Shigella and E. coli. Giardia lamblia was the most prevalent pathogen responsible for diarrhoea in 23.3% of cases followed by Entamoeba histolytica in 21.6%, Schistosoma mansoni in 5% and Hymenolepis nana and Ascaris lumbricoides in 1.6%. Concerning bacteria, Salmonella was detected (10%), Shigella (6.7%) and E. coli (13.3%). In conclusion, Cryptosporidium was not a cause of diarrhoea in patients with chronic liver disease.

The effect of calcium overdosages on the rate of eruption and periodontal ligament of lower incisor in albino rats

The study was conducted to determine the effect of calcium overdosages on the rate of eruption of lower incisor in albino rats. The experiment was carried out on a group of rats, and calcium was supplemented to the experimental animals in a dose of 450 mgm CaCl2/100 gm diet. The lower right incisor in control and experimental rats was transected out to the level of gingival margin and then the emerged portion of the growing tooth was measured twice weekly for the determination of eruption rate. The periodontal ligament of the tooth was examined to detect any histological change. The results indicated acceleration in rate of eruption of the tooth secondary to calcium administration, increase in thickness and vascular supply of its periodontal ligament and increase in the height of inner enamel epithelial cells and cellularity of enamel organ at the base of the root.