Low prevalence of the intact cag pathogenicity island in clinical isolates of Helicobacter pylori in Karachi, Pakistan

Clinical diseases that follow Helicobacter pylori infection are associated with expression of the cagA gene, a part of cytotoxin-associated gene pathogenicity island (cag-PAI). This study aims to determined whether or not the presence of cagA is associated with the presence of complete cag-PAI and to evaluate inflammatory changes associated with the five loci in the cag-PAI of H. pylori comprising cagA, cagA promoter region (cagAP), cagE, cagT and the left end of the cagA gene (LEC). H. pylori isolates were obtained from patients with dyspeptic symptoms. Clinical strains of H. pylori were screened by the polymerase chain reaction (PCR) for respective genes of the cag-PAI. Of 115 H. pylori isolates, 31 (28%) were positive for the five cag-PAI loci. H. pylori isolates with intact cag-PAI were associated with gastric carcinoma (GC; n=9 [60%]) and gastric ulcer (GU; n=5 [45%]) compared to non-ulcer dyspepsia (NUD; n=14 [18%]) (P=0.001 and P=0.049, respectively). In patients with intact cag-PAI, acute on chronic inflammation was present in 25 (81%) and was more common than chronic inflammation (P=0.013). The cagE and cagAP had deletions in 25 (37%) and 23 (35%) cases, respectively. The cagAP region was significantly associated with GC (n=12 [80%], P<0.001) and GU (n=9 [82%], P=0.001) compared to NUD (n=24 [30%] and with significant acute on chronic inflammation (n=40 [80%], P=0.007). The distribution of vacAs1a with intact cag-PAI in GC was 9 (60%) and in NUD was 10 (13%) (P<0.001). The presence of the cagA gene does not signify presence of an intact cag-PAI. Most of the H. pylori isolates studied had partial cag-PAI with missing cagE and cagA promoter regions.

Molecular dynamics simulation of nanocolloidal amorphous silica particles: part III

Explicit-solvent molecular dynamics simulations were applied to four pairs of amorphous silica nanoparticles, two pairs having a diameter of 2.0 nm and two pairs with diameter 3.2 nm. The silica nanoparticles were immersed in a background electrolyte consisting of Ca(2+) and Cl(-) ions and water and mean forces acting between the pair of silica nanoparticles were extracted at four different background electrolyte concentrations. The pH was indirectly accounted for via the ratio of silicon to sodium used in the simulations. Dependence of the interparticle potential of mean force on the center-of-mass separation and the silicon to sodium ratio (5:1 and 20:1) is demonstrated. A Si:Na(+) ratio of 5:1 gave more repulsive interparticle potentials and lower numbers of internanoparticle or "bridging" hydrogen bonds. Conversely a Si:Na(+) ratio of 20:1 yielded more attractive potentials and higher numbers of bridging hydrogen bonds. The nature of the interaction of the counterions with charged silica surface sites (deprotonated silanols) was also investigated. The effect of the sodium double layer on water ordering was observed. The number of water molecules trapped inside the nanoparticles was investigated, and at the highest background ionic concentrations were found to consistently behave in accordance with there being an osmotic pressure. This study highlights the effect of divalent (Ca(2+)) background ions on the interparticle potentials compared with previous work using monovalent (Na(+)) background ions. Mechanisms of coagulation and the stability of silica nanocolloids found from this work appear to be in agreement with findings from experiments described in the literature.

Prevalence and mode of spread of hepatitis B and C in rural Sindh, Pakistan

The aim of this study was to determine the prevalence and identify risk factors associated with the spread of hepatitis B and C in the rural areas of the upper Sindh Province, Pakistan. Included in this cross-sectional survey were 873 subjects belonging to 174 families residing in Jarwar, a small town of upper Sindh. A study using a systematic random sampling method was undertaken. One questionnaire per household was filled out and blood samples collected for hepatitis B surface antigen (HBsAg), hepatitis B core antibody total (HBcAb), and hepatitis C antibody (anti-HCV). HBsAg was reactive in 44 (5%), HBcAb in 494 (56.6%) and anti-HCV in 294 (33.7%). In the case control study, independent risk factors for exposure to hepatitis B were male sex, age greater than 16 years, absence of vaccination, previous history of jaundice, and family history of liver disease (adjusted odds ratios 1.4, 2.1, 1.7, 1.8 and 1.8, respectively). Independent risk factors for hepatitis C were age greater than 16 years, previous dental procedures, history of liver disease, lack of vaccination, and 10 or more injections in a year (adjusted odds ratios 3.7, 2.1, 2.4, 1.8 and 2.9, respectively). There was indication of intrafamilial and household clustering: for hepatitis C, parent to child p = 0.001, sibling-to-sibling p = 0.046; for hepatitis B, spouse-to-spouse p = 0.052 and parent to child p = 0.001. In conclusion, there is high exposure to hepatitis B and C in upper Sindh. There is a need to educate people about hepatitis B vaccination and iatrogenic factors responsible for transmission. The study suggests the possibility of intrafamilial spread of these viruses.

Mucormycosis in patients with complicated cirrhosis

INTRODUCTION

Rhino-orbito-cerebral mucormycosis is a rapidly progressive and fatal disease that mostly occurs in patients with diabetes mellitus and immunocompromised status. Antifungal therapy with surgical debridement is the standard of care. Patients with cirrhosis of liver are more prone to develop different infections. Many of these also show glucose intolerance or frank diabetes mellitus. Little is known about the clinical presentation and outcome of mucormycosis in patients with cirrhosis. Treatment is difficult due to underlying coagulopathy and hepatic dysfunction.

METHODS

Medical records of the past five years were searched for the cirrhotic patients admitted with associated diagnosis of mucormycosis or fungal infection. Six patients with mucormycosis were identified.

RESULTS

Out of six patients, five were male. Age range was 15-57 years. Cause of cirrhosis was hepatitis C in four patients, hepatitis B in one patient and autoimmune hepatitis in one patient. Two patients had hepatocellular carcinoma. Four patients had diabetes mellitus, of which one patient was also on steroids for the autoimmune liver disease. Four patients had spontaneous bacterial peritonitis at the time of admission. All six patients presented with rhino-orbitocerebral mucormycosis with nasal discharge and upper motor neuron signs. Diagnosis of mucormycosis was made by culture of biopsy and scrapings taken from the palate and nasal sinuses. These patients received amphotericin B. Four patients died while in the hospital, while two patients died within next few days after discharge.

CONCLUSION

Mucormycosis in cirrhosis is not very common and has a poor prognosis. Patients with advanced cirrhosis and diabetes mellitus are at risk of developing infection.

Concurrent malaria and enteric fever in Pakistan

INTRODUCTION

The precise incidence of concurrent malaria and enteric fever in most geographical areas is largely unknown, and no data on such an association exists in Asia. Because both malaria and enteric fever are hyperendemic in Pakistan, we sought to determine the frequency, epidemiology, and clinical and laboratory features of dual malaria and enteric fever in a tertiary care setting.

METHODS

We conducted a retrospective case-control study of 1,891 patients hospitalised with malaria over a ten-year period and identified 21 patients with concurrent culture-proven enteric fever.

RESULTS

Cases with dual infection had significantly more gastrointestinal symptoms at the time of admission, including nausea, vomiting, abdominal pain, and/or diarrhoea compared to matched control subjects with uncomplicated malaria (p-value is less than 0.006). Cases were more likely to have a continuous rather than intermittent fever (p-value is less than 0.0001), delayed defervescence in response to antimalarial treatment (p-value is less than 0.006), normal or low white blood cell counts (p-value is less than 0.04), relatively higher platelet counts among cases versus control (p-value is less than 0.05) and serum haemoglobin (p-value is less than 0.06), elevated alanine aminotransferase levels (p-value is less than 0.02), and a prolonged hospital stay (p-value is less than 0.03). The negative predictive values for gastrointestinal symptoms, continuous fever pattern and delayed defervescence were 80 percent, 72 percent and 74 percent, respectively.

CONCLUSION

Patients with malaria who have marked gastrointestinal symptoms, continuous pattern of fever and persistence of fever for more than 24 hours after appropriate antimalarial therapy, should be investigated or empirically treated for concurrent enteric fever. The absence of the above clinical features in patients with uncomplicated malaria should reassure physicians that there is no concurrent typhoid fever.

Pill-induced esophageal injury: endoscopic features and clinical outcomes

BACKGROUND AND STUDY AIMS

Pill-induced esophageal injury is a common but under-reported problem. The purpose of this study was to explore the clinical and endoscopic features, and the outcome of pill-related esophageal injury.

PATIENTS AND METHODS

Endoscopy records for the period from January 1997 to June 2003 were searched for reports of esophageal pathology. The records of patients with pill-induced esophageal injury were evaluated.

RESULTS

A total of 92 patients with pill-induced esophageal injury were identified (33 men, 59 women; mean age 59, range 25-87). Common symptoms were odynophagia (n = 69, 75 %), chest pain (n = 55, 60 %), vomiting (n = 53, 58 %), dysphagia (n = 31, 33 %), and hematemesis (n = 14, 15 %). The endoscopic findings in the esophagus were: erythema in 76 patients (83 %), erosions in 53 patients (58 %), ulcers in 24 patients (26 %), seven of which were "kissing" ulcers, esophageal ulcer with bleeding in 17 patients (18 %), and esophageal strictures in seven patients (8 %). The causative pills were nonsteroidal anti-inflammatory drugs in 38 patients (41 %), tetracyclines in 20 patients (22 %), potassium chloride tablets in nine patients (10 %), alendronate in eight patients (9 %), and other drugs in 17 patients (18 %). Underlying diseases included diabetes in 60 patients (65 %), ischemic heart disease in 39 patients (42 %), and hypothyroidism in four patients (4 %). The mean hospital stay was 1.94 days; 14 patients (15 %) required injection of epinephrine 1 : 10,000 to control bleeding; and two patients died.

CONCLUSIONS

Pill-induced injury may present as erosions, kissing ulcers, and multiple small areas of ulceration with bleeding, mainly in the middle third of the esophagus. Advanced age, female gender, diabetes, and ischemic heart disease were common associations. The majority of patients made an uneventful recovery.

Thymosin alpha 1 in combination with interferon alpha and ribavirin in chronic hepatitis C patients who are non-responders or relapsers to interferon alpha plus ribavirin

OBJECTIVE

Interferon alpha (IFN-alpha) with or without ribavirin is an approved therapy for patients with chronic hepatitis C. However, a sustained response is achieved in less than 40% of all treated cases. Retreatment of relapsers or non-responders usually fails. Thymosin alpha 1 (Ta-1) is a polypeptide with immunomodulatory properties that has been suggested to increase response rates in patients with chronic hepatitis C. The aim of present study was to evaluate the efficacy of a novel triple regimen which includes Ta-1 for relapsers and non-responders to the combination of TA-1 and ribavirin.

METHODS

In the present study, 11 patients who relapsed (n=5) or did not respond (n=6) to previous INF-alpha-based therapy were retreated with combination Ta-1, INF-alpha and ribavirin for 12 months, and followed up for a further six months.

RESULTS

Four out of five relapsers had a sustained response. One of the non-responders cleared the HCV RNA during the post-treatment follow-up. Minor adverse effects were observed during treatment with this combination therapy and no dose reduction or discontinuations were needed.

CONCLUSION

This data suggests that thymosin alpha 1 may add to the efficacy of INF-alpha plus ribavirin in the retreatment of relapsers or non-responders to previous INF-alpha-based hepatitis C therapy.

Improving kidney and live donation rates in Asia: Living donation

Organ transplantation started with organs donated by living subjects. Increasing demands brought cadaveric organ donation. The brain-death law, mandatory for this procedure, is prevalent in all countries involved in organ transplantation except Pakistan. Spain is the leading country in cadaveric organ donation (32.5 pmp). Despite the sources of living and cadaveric organs, both heart-beating and non-heart-beating, the gap between the demand and supply has widened. An example is the United States, where the numbers of patients on the waiting list for kidney transplantation have risen from 30,000 in 1988 to more than 116,000 in 2001. This has caused a resurgence in living donors all over the world. These can be related, unrelated, spousal, marginal, or ABO-incompatible donors. Family apprehensions, medical care costs, and nonexistent social security can be barriers to this form of organ donation. Unrelated organ donation can open the doors to commercialism. To make this process more successful, transplantation should be made reachable by all sectors of the population. This is possible when transplantation is taken to the public sector institutions and financed jointly by the government and community. To increase living organ donation especially in Asian countries, which face barriers of low literacy rates, ignorance, and cultural and religious beliefs, more efforts are needed. Public awareness and education play an important role. Appreciation and supporting the donors is necessary and justified. It is a noble act and should be recognized by offering job security, health insurance, and free education for the donor's children.

Adeno-associated viruses undergo substantial evolution in primates during natural infections

Adeno-associated viruses (AAVs) are single-stranded DNA viruses that are endemic in human populations without known clinical sequelae and are being evaluated as vectors for human gene therapy. To better understand the biology of this virus, we examined a number of nonhuman primate species for the presence of previously uncharacterized AAVs and characterized their structure and distribution. AAV genomes were widely disseminated throughout multiple tissues of a variety of nonhuman primate species. Surprising diversity of sequence, primarily localized to hypervariable regions of the capsid protein, was detected. This diversity of sequence is caused, in part, by homologous recombination of co-infecting parental viruses that modify the serologic reactivity and tropism of the virus. This is an example of rapid molecular evolution of a DNA virus in a way that was formerly thought to be restricted to RNA viruses.

Interleukin (IL) 1beta and IL-10 gene polymorphism in chronic hepatitis C patients with normal or elevated alanine aminotransferase levels

OBJECTIVE

To evaluate the frequency of cytokine gene single nucleotide polymorphisms (SNP) of IL-1beta and IL-10 at promoter sites -115 and -1082 respectively and their association with hepatocellular injury as suggested by alanine aminotransferase (ALT) level.

METHODS

Fifty six patients (31 males, 25 females) positive for HCV antibody were studied. Their mean age was 37.5 +/- 12.0 years (range 16-62). Fifty one were HCV RNA positive; 14 had normal and 37 elevated ALT levels. Type 3 was the predominant genotype. For cytokine polymorphism DNA was extracted from the whole blood. After amplification with polymerase chain reaction, biallelic polymorphisms of IL-1beta at -115 and IL-10 at -1082 promotor site were determined using sequence specific oligonucleotide primers.

RESULTS

IL-1beta-15 C allele was present in 49 (87.5%) and -115 T in 30 (53.6%) patients. Genotype CC was present in 26 (46%), TC 23 in (42%), and TT in 07 (12%). IL-10 -1082 A allele was seen in 50 (89.3%) and -1082 G in 35 (62.5%). Genotype AG in 29 (52%), AA in 21(37%), and GG in 06 (11%). Though greater number of HCV RNA positive patients with normal ALT had IL-10 -1082 AG genotype (10 out of 14), no statistically significant difference could be found in the genotype profile of the above promoter sites of IL-1beta and IL-10 in patients with normal or elevated ALT.

CONCLUSION

IL-1beta-115 C and IL-10 -1082A are the more frequent alleles in our patients. Genotypes L-1beta -115 CC and TC, and IL-10 -1082AG and AA are common while -115 TT and -1082 GG are less common. Any effect of IL-1beta and IL-10 gene polymorphism on the degree of hepatocellular injury may not be apparent by the ALT levels.

Rep/Cap gene amplification and high-yield production of AAV in an A549 cell line expressing Rep/Cap

Cell lines stably expressing rep/cap are important tools for studying adeno-associated virus (AAV) biology and producing AAV vectors. Several rep/cap cell lines have been isolated, each of which is based on HeLa cells. Infection of these cell lines with adenovirus for production of AAV vector is associated with substantial amplification of the rep/cap gene. Concerns over the presence of human papilloma viral (HPV) sequences in HeLa cells may limit use of such lines for production of clinical-grade vectors. Here we describe a non-HeLa-derived rep/cap cell line called K209, generated by stable transfection of A549 cells with a plasmid construct containing the P5 rep/cap cassette from AAV2. Infection of K209 cells with adenovirus leads to a 1000-fold amplification of the rep/cap gene with high-yield production of AAV vectors. The multiplicity of infection (MOI) of adenovirus that led to maximum amplification of the rep/cap gene and high-level production of AAV is 10 times higher in the HeLa-based cell line than that required in K209 cells. Our data suggest that papilloma-derived gene products present in HeLa cells are not required for high-yield production of AAV vectors.

Prevalence of histological reflux oesophagitis in H. pylori positive patients: effect of density of H. pylori and activity of inflammation

OBJECTIVE

Recently there has been a great interest in the role of Helicobacter pylori in gastroesophageal reflux disease. Many studies do not show any significant difference in the overall prevalence of H. pylori in patients with endoscopic oesophagitis and controls. In this prospective study we assessed the influence of H. pylori density and activity of inflammation in different parts of stomach on histological oesophagitis.

METHODS

One Hundred and forty consecutive patients undergoing endoscopy for dyspepsia and heartburn were evaluated. Three biopsies were taken from antrum and two each from corpus, cardia and lower oesophagus. Urease test (CLO test) was performed. Density and activity of infection was assessed in a semi-quantitative way.

RESULTS

One Hundred and Fourteen (81%) patients from the 140 endoscoped, were positive for H. pylori and had H. pylori positive antral gastritis. Of these 114 cases, H. pylori were detectable in 104 (91%) of biopsies taken from corpus and 96 (84%) of biopsies from cardia. There was a strong correlation of density of H. pylori (0-3) in antrum with body and of body with cardia by Spearman correlation tests (p = 0.000). But H. pylori were more dense in antrum as compared to corpus and in corpus as compared to cardia (p = 0.0000 and 0.0003 respectively by Wilcoxon's rank test). Neutrophil activity and degree of mononuclear infiltrate were also greater in antrum as compared to corpus (p = 0.000 and 0.059). The activity and degree of inflammation was not significantly different in corpus-cardia pair. Out of 114 H. pylori positive patients, 75 had histological oesophogitis (p = 0.855). After excluding cases of hiatal hernia (H.H) and gapping lower oesophageal sphincter (LOS), number of H. pylori positive patients decreased to 73, out of these 50 had histological oesophagitis (p = 0.103). In all H. pylori positive patients with histological oesophagitis, H. pylori density (1-3) in antrum correlated with severity of oesophagitis (P = 0.011). Neutrophil activity in antrum and corpus also correlated with the severity of histological oesophagitis (P = 0.024 and 0.035 respectively). Correlation further improved after excluding cases of HH and gapping LOS (P = 0.002 for H. pylori density and 0.026 and 0.004 for activity in antrum and corpus). No correlation could be found of density and activity of infection in cardia with histological oesophagitis.

CONCLUSION

Our H. pylori positive patients had more dense and severe infection in antrum. Those who had histological oesophagitis in addition showed a positive correlation of the density of H. pylori in antrum and neutrophil activity in antrum and corpus with the severity of histological oesophagitis.

Triple therapy with clarithromycin, omeprazole, and amoxicillin for eradication of Helicobacter pylori in duodenal ulcer patients in Asia and Africa

BACKGROUND

Studies assessing the efficacy of triple therapy containing clarithromycin and amoxicillin for the eradication of Helicobacter pylori infection and healing of duodenal ulcers in Asian and African countries are limited.

AIM

To determine the efficacy and safety of 1-week triple therapy with omeprazole, amoxicillin and clarithromycin for eradicating H. pylori infection in patients with active duodenal ulcer living in Asian and African regions.

METHODS

This was an open-label, multicentre study in 11 centres in Asia and Africa. Patients with endoscopy-proven duodenal ulcer and who were H. pylori-positive were treated with clarithromycin 500 mg, omeprazole 20 mg, and amoxicillin 1000 mg, all given twice daily for 7 days. Upper endoscopy was repeated at week 6 to check for ulcer healing and H. pylori status.

RESULTS

A total of 117 patients were recruited. H. pylori eradication rates were 85% by per protocol analysis and 80% by intention-to-treat analysis. Ulcer healing was found in 94% of subjects (per protocol analysis). Clinical success, measured by change of pre-treatment ulcer symptoms, was strongly supported by complete resolution or improvement in 100% of the evaluable patients (per protocol analysis). Since treatment-related adverse events, when present, were largely mild or moderate, the triple therapy regimen was considered safe.

CONCLUSION

Seven-day triple therapy with omeprazole, amoxicillin, and clarithromycin was efficacious for treating Asian and African patients with duodenal ulcer disease associated with H. pylori infection, and the treatment regimen was well-tolerated.