Teaching biostatistics and epidemiology in a postgraduate medical institution: are we going in the right direction?

We examined the attitude and knowledge of 40 supervisors and trainees as well as the impact of workshops on statistical thinking and analytical processes in a medical facility in Pakistan: 45% thought that statistics and epidemiology should be left to professional statisticians; 86% of the trainees and 58% of the supervisors, however, thought that statistics should be taught as a full-time subject. The majority of trainees (86%) were dissatisfied with the workshops compared to 33% of supervisors. Our findings indicate an urgent need to revise our approach to teaching statistics and epidemiology.

Prognostic significance of genotyping Helicobacter pylori infection in patients in younger age groups with gastric cancer

BACKGROUND

Malignant tumours of the stomach are common, but the incidence of stomach cancer varies from country to country, probably a result of genetic, epigenetic and environmental factors. Stomach cancer often occurs in older people whose stomachs produce only small quantities of acid. Although infection with Helicobacter pylori has been proven beyond doubt in the aetiopathogenesis of various gastric disorders, not much is known about the genotypes of H pylori infection in early-onset gastric cancer.

AIM

To ascertain the genotypes of H pylori in gastric cancer.

METHODS

Ninety-two patients were separated into three groups on the basis of their endoscopic findings: group 1, gastric cancer; group 2, gastric ulcer; group 3, non-ulcer dyspepsia. Gastric biopsy specimens were obtained for culture and DNA isolation; additional specimens were taken from subjects with gastric cancer for histopathological analysis. Amplification was performed using specific oligonucleotide primers to obtain genotypic data. Four samples from each group were randomly selected for sequence analysis.

RESULTS

Genotypic analysis showed cagT+ve/hrgA+ve/cagA+ve/cagE+ve/vacAs1+ve to be highly prevalent in 79% of cases of H pylori infection. This genotype was found in 88% of subjects in group 1 and 78% in group 2. Intestinal-type adenocarcinoma was found in 35 subjects (83%), 32 (9%) of which harboured this genotype. Sequence analysis showed no significant strain-specific variations.

CONCLUSIONS

Certain genotypes of H pylori have higher predictive value for the development of intestinal-type carcinoma at an early age. Genotyping of H pylori may well be a useful tool for screening people at increased risk of developing malignancy.

Safety and efficacy of autologous bone marrow stem cell transplantation through hepatic artery for the treatment of chronic liver failure: a preliminary study

This study was performed to determine the safety and tolerability of injecting autologous bone marrow stem cells (BMC) (CD34+) into four patients with liver insufficiency. The study was based on the hypothesis that the CD34+ cell population in granulocyte colony stimulating factor (G-CSF) mobilized blood and autologous bone marrow contains a subpopulation of cells with the potential for regenerating damaged tissue. We separated the CD34+ stem cell population from the bone marrow. The potential of the BMC to differentiate into hepatocytes and other cell lineages has already been reported. Several reports have also demonstrated the plasticity of hematopoietic stem cells to differentiate into hepatocytes. Recently Sakaida demonstrated reduction in fibrosis in chemically induced liver cirrhosis following BMC transplantation. From a therapeutic point of view, chronic liver cirrhosis is one of the targets for BMC transplantation. In this condition, there is excessive deposition of extracellular matrix and hepatocyte necrosis. Encouraged by this evidence that the CD34+ cell population contains cells with the potential to form hepatocyte-like elements, four patients with liver insufficiency were given G-CSF to mobilize stem cells. CD34+ cells (0.1 x 10(8)) were injected into the hepatic artery. No complications or specific side effects related to the procedure were observed; four patients showed improvements in serum albumin, bilirubin and ALT after one month from the cell infusion.

Management of hyperbilirubinemia in biliary atresia by hepatic progenitor cell transplantation through hepatic artery: a case report

Cholangiodestruction of bile ducts leads to biliary atresia, a rare disease characterized by intrahepatic and extrahepatic biliary inflammation. If the intrahepatic biliary tree is unaffected, surgical reconstruction by the Kasai procedure of hepatoportoenterostomy of the extra hepatic biliary tract is possible. Untreated, this condition leads to cirrhosis and death within the first year of the life. If the atresia is complete, liver transplantation is the only option. As a result of the shortage of donor livers, hepatocytes have been infused over the past two decades, providing proof of the concept that cell therapy can be effective for the treatment of liver diseases. In the present study, we report a confirmed case of a girl of 1 year of age with increased bilirubin of 28.5 mg/dL and pediatric end-stage liver disease score 20. Biochemical liver function tests showed cholestasis (elevated cholesterol and gamma-GTs) and increased ALT, total bilirubin, conjugated bilirubin, and ALP. The patient was treated with hepatic progenitor cell infusion through the hepatic artery. The total bilirubin and conjugated bilirubin started decreasing during the first month after cell infusion. The level of total bilirubin maintained a threefold decrease after months of cell infusion. The conjugated bilirubin was 16.35 mg/dL before cell infusion, decreasing to eightfold after cell infusion. After 2 months of cell infusion, hepatobiliary scintigraphy showed increased liver cell function. This case demonstrated the efficacy and functionality of hepatic progenitor cells for the management of biliary atresia. Further, as there was a decrease in serum bilirubin, it showed that there was some percentage of the engraftment of the infused cells. As the procedure is simple and the patient has tolerated the infusion therapy, it might be repeated to manage biliary atresia.

The management and outcome of anastomotic leaks in colorectal surgery

PURPOSE

Anastomotic leaks in colorectal surgery are associated with significant morbidity and mortality and may result in poor functional and oncological outcomes. Diagnostic difficulties may delay identification and appropriate management of leaks. The aim of this study was to look at the diagnosis, clinical management and outcomes of anastamotic leaks in our department.

METHOD

A retrospective audit and case note review of all patients who underwent the formation of a colorectal anastomosis between January 1996 and December 2002 (n = 1421) was performed. An anastomotic leak was defined as sepsis identified to have arisen from an anastomosis that subsequently required surgery, radiological drainage or intravenous antibiotics. Forty-one patients (25 male, 16 female) with a median age of 60 years (range 7-89 years) were identified as having suffered an anastomotic leak.

RESULTS

The median time to diagnosis of an anastomotic leak following surgery was 7 days (range 3-29). At re-operation, 21 patients (51%) underwent formation of a stoma, and any who required the anastomosis to be formally taken down have been left with a 'permanent' stoma. Currently only four of 12 patients (33%) who required a stoma for an anastomotic leak following anterior resection have undergone stoma reversal. Eleven of 16 patients (69%) who had received a stoma following another colorectal procedure had undergone stoma reversal. The mortality associated with an anastamotic leak in this series was 5% (n = 2).

CONCLUSION

Although anastomotic leaks following colorectal surgery are associated with significant morbidity and stoma formation, early and aggressive management should result in a low overall mortality. If an anastomosis is taken down following an anastomotic leak after anterior resection, this will usually result in a 'permanent' stoma.

Tumor necrosis factor alpha enhances the sensitivity of rat trigeminal neurons to capsaicin

Tumor necrosis factor alpha (TNFalpha), a pro-inflammatory cytokine, enhances the development of pain and hyperalgesia, although the molecular mechanisms are not well understood. This study evaluated the hypothesis that TNFalpha increases the sensitivity of rat trigeminal neurons to capsaicin via two different mechanisms triggered by either brief or sustained exposure to the cytokine. A brief (5 min) application of TNFalpha significantly sensitized capsaicin-evoked accumulation of intracellular calcium ([Ca2+]i) (226.4+/-37.7 nM vs. 167.5+/-31.3 nM) and increased capsaicin-evoked nocifensive behavior (78.3+/-9.7 vs. 30.9+/-3.6 s) as compared with vehicle pretreatment (P<0.01 for both). Sustained (30 min to 4 h) exposure of cultured neurons to TNFalpha evoked a twofold increase in mRNA transcript (P<0.05) and protein levels (P<0.01) of transient potential receptor vanilloid type 1 (TRPV1). This long-term up-regulation of TRPV1 expression by TNFalpha correlated with enhancement in capsaicin-induced calcitonin gene-related peptide release (P<0.05). Demonstration of colocalization of TNFalpha receptor subtypes I and II with TRPV1 in almost all (>90%) TRPV1 expressing neurons provides evidence consistent with a direct interaction on the same subpopulation of sensory neurons. In summary, our data demonstrate that TNFalpha directly enhances the sensitivity of rat trigeminal neurons to capsaicin via both rapid, non-genomic mechanisms as well as sustained genomic regulation in TRPV1 expression. Thus, increased sensitization and up-regulation of TRPV1 constitutes a potential mechanism by which TNFalpha mediates inflammatory hyperalgesia and pain.

The Bradford Burn Study: the epidemiology of burns presenting to an inner city emergency department

OBJECTIVE

The Bradford Burn Study prospectively reviewed all burn attendances at a single emergency department in the UK over a 1 year period. The study reviewed the epidemiology, demographics and outcomes of all patients entered into the study.

DESIGN AND SETTING

A 12 month prospective study of burn injuries attending an inner city emergency department serving a population of 1 million people.

RESULTS

460 patients were enrolled into the study. Average patient age was 22.7 years, male: female ratio was 1:1.4, and children <10 years of age accounted for 36% of the case mix. Asian patients accounted for 41% of all attendances; 85% of the cases in the study were accidental in nature, with scalds accounting for 52% of the injuries. Final outcomes were as follows: 54% of patients were reviewed by the emergency department physicians and only one of these patients ultimately needed skin grafting; 19% had follow-up by their primary care physicians; 12% were reviewed by plastic surgeons, and 5% were admitted; of those patients admitted, 16% needed surgery; only 12 patients (3%) were admitted to specialised burn units.

CONCLUSIONS

Emergency departments manage patients with burns well, and referrals to plastic surgery departments are appropriate. The majority of burns can be prevented by addressing educational issues and vulnerable sections of the population.

A simple multiplex PCR assay for diagnosing virulent Helicobacter pylori infection in human gastric biopsy specimens from subjects with gastric carcinoma and other gastro-duodenal diseases

AIM

To evaluate and develop a multiplex polymerase chain reaction (PCR) assay for diagnosing and specific identification of virulent Helicobacter pylori strains and their main virulence genes cagA, cagE, cagT, vacA and hrgA.

METHODS AND RESULTS

Genomic DNA from 82 gastric tissues was screened. A master pool of all the ingredients of multiplex reaction was prepared for amplification. Amplicons were sequenced to confirm the amplification of each target genes. Multiplex PCR assay was able to detect all the five target genes in 81.7% and deletions in one or more loci among 18.3%. Genotype cagT +ve/hrgA +ve/cagA +ve/cagE +ve/vacAs1 +ve was more predominant in this study population (67.07%). hrgA, cagT, cagE and cagA genes were present in 100%, 92.7%, 85.4% and 81.7% of the subjects, respectively. The vacAs1 subtype had higher prevalence frequency in patients with overt gastrointestinal disease (78.57%) than with GERD (gastro-esophageal reflux disease) and NUD (non-ulcer dispepsia) (50%).

CONCLUSIONS

The multiplex PCR assay developed herein was able to genotype H. pylori isolates based on the main virulence genes.

SIGNIFICANCE AND IMPACT OF THE STUDY

The ability to identify H. pylori and the majority of their virulence gene markers by multiplex PCR assay represents a considerable advancement over other PCR-based methods for genotyping H. pylori from large population, and can be explored to gain insights at the genotypic variability exhibited by this pathogen.

Study of genetic divergence among wheat genotypes through random amplified polymorphic DNA

The degree of genetic divergence was estimated in seven wheat genotypes, six exotic genotypes and one local variety, through random amplified polymorphic DNA methodology. A total of 112 DNA fragments were generated by the 15 random primers, with an average of about 7.4 bands per primer. Among the 112, 50 fragments showed polymorphism among the seven wheat genotypes. Nei and Li's similarity matrix ranged from 86.2 to 93.0%, which indicated a narrow genetic base among the genotypes. The maximum similarity, 93.0%, was observed between 12WLRG/1-12 and WL-43. The local variety, Chenab-70, showed the lowest similarity with the exotic types. We conclude that random amplified polymorphic DNA analysis can be used for the characterization and grouping of wheat genotypes; these results will be helpful in our wheat breeding program.

Impact of household hygiene and water source on the prevalence and transmission of Helicobacter pylori: a South Indian perspective

INTRODUCTION

In developing countries, the Helicobacter pylori (H. pylori) infection rate is high, especially in lower socioeconomic groups. The populace in developing countries lives in conditions that are highly conducive to the acquisition of microorganisms. Poor hygiene, crowded household conditions and deficient sanitation mark their day-to-day life. We aimed to find out the roles of household hygiene and water source in the prevalence and transmission of H. pylori infection among the South Indian population using polymerase chain reaction (PCR) assay.

METHODS

The selected population consisted of 500 adults of varying ages ranging from 30 to 79 years, with upper gastrointestinal tract symptoms. Each participant in the study was given a questionnaire to complete. Samples to assess H. pylori infection included three gastric biopsies (two from the antrum and one from the corpus region). Infection was detected by PCR amplification of the 16S rRNA gene of H. pylori. The data was then examined statistically by univariate and multivariate analyses.

RESULTS

The overall prevalence of H. pylori was detected to be 80 percent. Prevalence increased with an increase in age and it was found to be 90 percent in the 70-79 year age group (p-value is less than 0.01). The prevalence of infection among people who drank water from wells was 92 percent compared with 74.8 percent of those who drank tap water (p-value is less than 0.001). H. pylori infection prevalence was found to be higher in people with low clean water index (CWI) (88.2 percent) than in those with higher CWI (33.3 percent) (p-value is less than 0.001). While the prevalence of H. pylori in the subjects with lower socioeconomic status was 86.1 percent, in higher groups, it was 70 percent (p-value is less than 0.001). The prevalence of H. pylori was also found to be higher in subjects who lived in overcrowded houses. It was 83.7 percent with high crowding index, 76.6 percent with medium crowding index, and 71.3 percent with low crowding index (p-value is less than 0.05).

CONCLUSION

The results of the present study suggest that the risk of acquisition and transmission of H. pylori can be prevented to a large extent by following improved household hygienic practices, proper waste disposal measures as well as the regular use of boiling water for drinking purposes.

Digestive tract schwannoma

BACKGROUND

Digestive tract schwannomas (DTS) are rare benign mesenchymal tumours usually affecting females between 30 and 60 years old.

METHODS

We retrospectively reviewed 2 cases of DTS treated at our hospital. The first case is a 38-year-old female with gastric schwannoma presenting with acute upper gastro-intestinal bleeding. The second case is a 36-year-old female with mesenteric schwannoma presenting with chronic right iliac fossa pain. Both patients underwent surgical resection of the tumour.

RESULTS

Histology and immunohistochemistry revealed the typical appearance of a DTS.

CONCLUSION

DTS is most commonly found in the stomach. It is usually asymptomatic but can present with variable symptoms. Definitive diagnosis can only be made on the basis of immunohistochemistry. Surgical resection is the treatment of choice.

Clinical characteristics of pulmonary tuberculosis in adult Pakistani patients with co-existing diabetes mellitus

A review was made of the records of all patients with pulmonary tuberculosis and diabetes mellitus admitted over a 5-year period to a teaching hospital in Karachi, Pakistan. Among 42358 patients, the total number with both tuberculosis and diabetes was 173. The prevalence of tuberculosis in diabetic patients was 10-times higher than in non-diabetic patients and prevalence increased with duration of diabetes. The lower lung field was most frequently involved, followed by the upper and middle. Bilateral involvement was seen in half and an associated pleural effusion in one-third of the patients. Cavitating lesions were seen in 32% of men and 15% of women.

Transdiaphragmatic intercostal hernia due to chronic cough

Intercostal transdiaphragmatic hernia is a rarely reported lesion. Trauma is the commonest cause. We report a 75-year-old man who presented with transdiaphragmatic intercostal hernia due to chronic cough. He recovered after surgical repair.

Elevated serum CCL2 concomitant with a reduced mycobacterium-induced response leads to disease dissemination in leprosy

Mycobacterium leprae and Mycobacterium tuberculosis are successful intracellular pathogens which down regulate host immune responses. T-cell interferon-gamma (IFNgamma) and macrophage tumour necrosis factor-alpha (TNFalpha) activate chemokines such as, C-C chemokine ligand-2 (CCL2) and CCL5, which play a role in granuloma formation. Lepromatous leprosy is characterized by defective granulomas with lowered T-cell- and macrophage-mediated responses. Tuberculosis (TB) can be localized to the lung, whereby discreet granulomas are formed. The role of chemokines in leprosy infections is as yet unclear. We compared chemokine responses in lepromatous leprosy and pulmonary tuberculosis patients. Circulating serum CCL2 was raised while CCL5 was lowered in leprosy, as compared with TB patients and healthy controls. However, both Mycobacterium bovis BCG- (P=0.08) and M. leprae-induced (P=0.05) CCL2 secretion was reduced in leprosy. In leprosy, BCG induced greater CCL2 (P=0.01), TNFalpha (P=0.02) and somewhat greater CCL5 (P=0.08) than M. leprae, while CXCL8 induction was comparable. Overall levels of Mycobacterium-induced CCL2, TNFalpha and CXCL8 were two to threefold lower, and CCL5 was 10-fold lower in leprosy as compared with TB. Reduced inducible CCL2 combined with a lowered TNFalpha response in lepromatous leprosy may contribute to the unrestricted growth and dissemination of mycobacteria found in the disease.

Prevalence study to elucidate the transmission pathways of Helicobacter pylori at oral and gastroduodenal sites of a South Indian population

INTRODUCTION

Since the discovery of Helicobacter pylori (H. pylori), much progress has been made worldwide in the field of its epidemiology. In spite of these advancements, many aspects of epidemiology still remain unclear, particularly among populations with low socio-economic status. The present study was designed to elucidate the different routes of transmission of H. pylori in the Hyderabad (South India) population and to investigate the impact of certain factors, such as age, gender, and lifestyle.

METHODS

Samples used for the study included saliva and biopsy samples of 400 symptomatic subjects from Hyderabad, India. The patients were retrospectively grouped, based on histopathology of the biopsy and 16S rRNA amplification of both saliva and biopsy as H. pylori positive and negative.

RESULTS

This study showed that the prevalence of H. pylori in both saliva and biopsy samples increased with age. In addition, the H. pylori infection was found more commonly in the saliva and biopsy samples among males (64 percent and 60 percent, respectively) than females (53.3 percent and 64 percent, respectively). Similarly, 71.6 percent and 73.5 percent of those who consumed municipal water acquired H. pylori (which were respectively found in their saliva and biopsy samples) compared to a lesser proportion (12.6 percent and 12.6 percent, respectively) of those who consumed boiled or filtered water. The study also found that subjects who preferred home-cooked food (57.1 percent and 57.7 percent) showed a lower prevalence of H. pylori in saliva and biopsy samples, respectively, compared to those (80 percent and 88 percent) who frequently ate out.

CONCLUSION

The results of the present study suggest that besides the oral-oral route, the transmission of H. pylori also takes place through the consumption of food prepared under unhygienic conditions. Consumption of municipal tap water also has a high impact in the transmission of H. pylori.

Burn patterns of Asian ethnic minorities living in West Yorkshire, UK

Whereas burn morbidity and mortality have been well studied among natives of Southeast Asia, few have studied the epidemiology of burn injury among UK Asian ethnic minority immigrants. A 1 year prospective study of all patients presenting with burns to Bradford Royal Infirmary was carried out. Four hundred and sixty patients were studied, 188 (41%) were Asian ethnic minorities. The average patient age was 17 years for the Asian group and 27 years for the non-Asian patients. Contact burns were responsible for 29% of injuries in Asian patients and 19% in the other group. Thirty-seven percent of contact burns in the Asian ethnic minority group were caused by hot irons. Eleven percent of Asian patients had treated their burn with inappropriate remedies including saiti, butter, and toothpaste. There were no significant differences between Asian and non-Asian patients in terms of large or deep burns, nor in mortality. Morbidity and mortality from burn injury among UK Asian patients and other groups in the UK are similar; however, a disproportionate number of Asian patients sustain smaller burns. Much of this is behaviour related, and it is hoped that through preventative measures a marked reduction in the number of Asian ethnic minority burns can be achieved.

Pre-clinical assessment of DRF 4367, a novel COX-2 inhibitor: evaluation of pharmacokinetics, absolute oral bioavailability and metabolism in mice and comparative inter-species in vitro metabolism

The aim of this study was to characterize the pharmacokinetics and determine the absolute bioavailability and metabolism of DRF 4367, a novel COX-2 inhibitor, in mice. In addition, the in vitro metabolism of DRF 4367 was studied in mouse, rat, dog, monkey and human liver microsomes. Following oral administration, maximum concentrations of DRF 4367 were achieved after about 1 h. Upon intravenous (IV) administration, the concentration of DRF 4367 declined in a bi-exponential fashion with a terminal elimination half-life of 4.0 h. The elimination half-life was unchanged with route of administration. The volume of distribution and systemic clearance of DRF 4367 in mice were 0.80 l h(-1) kg(-1) and 0.14 l kg(-1), respectively, after IV administration. The absolute oral bioavailability of DRF 4367 was 44%. In all species of liver microsomes examined, the primary route of metabolism for DRF 4367 was demethylation of benzyl methoxy to form a hydroxy metabolite (M1). The formation of this metabolite was mediated by CYP2D6 and CYP2C19 enzymes. M1 was not found to possess COX-2 inhibitory activity. Chemical-inhibition studies showed that quinidine (selective for CYP2D6) and ticlopidine (selective for CYP2C19) inhibited the formation of the hydroxy metabolite of DRF 4367, whereas potent inhibitors selective for other forms of CYP did not inhibit this oxidative reaction. Upon oral or IV administration of DRF 4367 to mice, unchanged DRF 4367, M1, the O-glucuronide conjugate of M1 (M1-G) and the O-sulfate conjugate of M1 (M1-S) were identified in bile.