Native pulmonary valve endocarditis requiring pulmonary valve replacement in adulthood: a case series.

Native pulmonary valve endocarditis is a rare phenomenon as native valve endocarditis tends to typically affect the left sided heart valves. However, the right-sided heart valves can be affected in patients with a history of intravenous drug use, whereby the tricuspid valve is most commonly affected. We present two cases who were diagnosed with native pulmonary valve endocarditis in the absence of congenital heart disease. In the first case, the native pulmonary valve endocarditis was probably a derivative of compounding factors of an enlarged underlying pulmonary artery and staphylococcal bacteraemia. In the second case, a common causal organism of native valve endocarditis following dental treatment and the resultant echocardiography findings was of significant interest. In summary, native pulmonary valve endocarditis is relatively rare complication in the adult population, especially in the absence of congenital heart disease.

Off-pump external pericardial patch repair for post-infarct left ventricular free wall rupture: a case series.

We describe an off-pump surgical approach to this challenging condition supported by our results from a case series, which would add to existing literature in the management of this life-threatening complication. We identified seven patients who underwent surgical intervention for left ventricular (LV) free wall rupture at our institution. They were all diagnosed to have cardiac tamponade secondary to free wall rupture of the LV in the presence of acute myocardial infarction. The surgical technique comprised of utilizing an external pericardial patch which was secured using surgical biological glues (fibrin-based sealants or gelatin hydrogels). The 30-day mortality, 1-year survival and 2-year survival were 57, 42 and 42%, respectively. Advanced age, female gender and use of cardiopulmonary bypass were characteristics that were not significantly associated with survival. We advocate the use of an off-pump external pericardial patch repair strategy as a 'bridge to recovery' in this extremely high-risk group of patients.

Delayed cardiac tamponade following blunt chest trauma due to disruption of fourth costal cartilage with posterior dislocation.

Cardiac tamponade is a recognised sequelae of non-penetrating and penetrating chest trauma. Delayed cardiac tamponade has been described following blunt chest trauma. We present a 29 year-old gentleman who had initially presented to peripheral district general hospital following direct blunt chest wall trauma. His initial trauma CT demonstrated a small mediastinal haematoma and large left haemopneumothorax and disruption/dislocation of the costal cartilage. He initially underwent a thoracoscopic procedure uneventfully. He then had worsening chest radiograph appearances with enlarging cardiac contours. Transthoracic echocardiography confirmed cardiac tamponade. He underwent creation of a pericardial window and excision of the protruding fourth costal cartilage.

Transoral robotic resection of oropharyngeal synovial sarcoma in a pediatric patient.

Localized synovial cell sarcomas are treated with surgical resection followed by chemo-radiation. Surgical resection of synovial sarcoma of the oropharynx and hypopharynx involves lip-splitting mandibulotomy resulting in treatment related morbidity. We report the successful use of Trans Oral Robotic Surgery for resection of localized synovial sarcoma of the lateral pharyngeal wall in a 15 year old patient. We were able to achieve negative surgical margins and avoid open surgery with its associated morbidity. At 2 years follow-up, patient is disease free, with no deficits in speech or swallowing functions and no cosmetic deformity.

HLA polymorphism in six ethnic groups from Pakistan.

The extreme polymorphism found at some of the loci of the HLA system has made it an invaluable tool for population genetic analyses. In this study the genetic polymorphism of six Pakistani ethnic groups was investigated at the HLA-A, -B, -C, -DRB and DQB1 loci using polymerase chain reaction with sequence specific primers. The groups included in this study are the Baloch, Brahui and Sindhi from the south and the Burusho, Kalash and Pathan from the north of Pakistan. The allele frequencies, three-locus haplotype frequencies for HLA-A, -C, -B and HLA-A, -B, -DRB1 are given. Variation in the allele and haplotype distribution between the six Pakistani ethnic groups was observed. A phylogenetic tree and correspondence analysis based on HLA-A, -B, -C, -DRB1 and -DQB1 allele frequencies revealed the Kalash population to be distinct from the remaining Pakistani populations. The Baloch and Brahui were closely related to one another. The Sindhi were closer to the Pathan and Burusho populations than to the neighboring Baloch and Brahui populations, indicating admixture between the northern and southern populations of Pakistan. A phylogenetic tree and correspondence analysis comparing the Pakistani populations with various other world populations showed that the Pakistani ethnic groups lie within the cluster of Asian Indian populations. The three-locus haplotypes found in the Pakistani populations suggest an influence from Caucasian and Oriental populations.

Frequency of CCR5 Gene 32-bp deletion in Pakistani ethnic groups.

CCR5 is a G-protein-coupled chemokine receptor that is used as a co-factor by macrophage-tropic (M-tropic) isolates of human immunodeficiency virus-1 (HIV-1) to gain entry into host cells. A 32-bp deletion in the CCR5 gene (CCR5-Delta32) leads to the production of an altered gene product that prevents HIV-1 from entering the host cell. This study was carried out to determine prevalence of CCR5-Delta32 allele frequency in a large Pakistani population sample (n = 821) representing 10 ethnic groups. No individual was homozygous for the mutant allele and the frequency of the CCR5-Delta32 allele ranged from 0.62% to 3.57%. The CCR5-Delta32 allele frequency was generally lower in populations from southern Pakistan. The overall frequency of the CCR5-Delta32 allele in Pakistan was 2.31%, which is much lower than that found in European populations and similar to that in the Middle East. This is consistent with the historical records and genetic data that indicate a close genetic affinity among these populations. This study demonstrates that the Pakistani population is highly susceptible to M-tropic isolates of HIV-1 and public health measures need to be enforced with urgency if Pakistan is to avoid an HIV epidemic.

P53 mutations, polymorphisms, and haplotypes in Pakistani ethnic groups and breast cancer patients.

Inactivation of the p53 gene has been found to be associated with the pathogenesis of several neoplasias. Three biallelic polymorphisms in the p53 gene have been linked to predisposition to the development of various malignancies. These include a 16-bp duplication in intron 3 and BstU I and Msp I restriction fragment length polymorphisms (RFLPs) in exon 4 and intron 6, respectively. The prevalence of these polymorphisms was studied in breast cancer patients and nine major ethnic groups of Pakistan. Differences in allele frequencies for all three polymorphisms were observed among the various ethnic groups and breast cancer patients. The absence of the 16-bp duplication was common among the northern ethnic groups, being highest in the Hazara (0.90). The Msp I A1 allele frequency in the southern Makrani population was significantly higher in comparison with the other ethnic groups. In the cancer patients, the absence of the 16-bp duplication in combination with the BstU I Pro and absence of Msp I restriction site were the most frequent. In these patients, ten substitution mutations were found in the p53 gene, seven of which have been reported previously for breast cancer. The remaining three mutations have been found in other malignancies, but not in carcinoma of the breast.

Identification and characterisation of novel human Y-chromosomal microsatellites from sequence database information.

1.33 Mb of sequence from the human Y chromosome was searched for tri- to hexanucleotide microsatellites. Twenty loci containing a stretch of eight or more repeat units with complete repeat sequence homo-geneity were found, 18 of which were novel. Six loci (one tri-, four tetra- and one pentanucleotide) were assembled into a single multiplex reaction and their degree of polymorphism was investigated in a sample of 278 males from Pakistan. Diversities of the individual loci ranged from 0.064 to 0.727 in Pakistan, while the haplotype diversity was 0.971. One population, the Hazara, showed particularly low diversity, with predominantly two haplotypes. As the sequence builds up in the databases, direct methods such as this will replace more biased and technically demanding indirect methods for the isolation of microsatellites.

Occurrence and susceptibility to antibiotics of Shigella species in stools of hospitalized children with bloody diarrhea in Pakistan.

The aim of the present investigation was to study the frequency of Shigella spp. in patients with bloody diarrhea in Pakistan and the susceptibility of isolated Shigella to three antibiotics: ampicillin, cotrimoxazole and nalidixic acid. In addition, the frequency of Campylobacter and Salmonella was also determined. Stool samples (n = 152) were collected from 152 diarrheic children less than six years of age passing blood and mucus in their stools who were admitted to Paediatric Department of Mayo Hospital in Lahore, Pakistan from June to September 1990. The samples were cultivated on standard media for Shigella, Campylobacter, and Salmonella. Susceptibility of Shigella isolates was tested by disk diffusion method. The frequency of isolation was 19.1% for Shigella spp., 7.9% for Campylobacter, and 4.6% for Salmonella. Shigella flexneri (7.9%) was the most frequently isolated species, followed by S. dysenteriae (6.6%), S. boydii, (3.3%) and S. sonnei (1.3%). All Shigella isolates were susceptible to nalidixic acid (100%), while only a few were susceptible to cotrimoxazole (7.0%) and ampicillin (3.5%). In Pakistan, self-medication and purchases of drugs without a prescription are commonly practiced. Thus, there is a greater possibility of development of resistant strains due to over use of antibiotics.

Flies and water as reservoirs for bacterial enteropathogens in urban and rural areas in and around Lahore, Pakistan.

The study was conducted to isolate and characterize campylobacter, enterotoxigenic Escherichia coli-labile toxin (ETEC-LT), shigella and salmonella in flies and water. The material for the study, flies (n = 300) and water samples (n = 148), was collected from different localities in and around Lahore, Pakistan. Cultivation of the samples was performed on conventional standard media. Membrane filtration technique was used for water prior to culture. Determination of ETEC-LT was done by GM1 ELISA. Results of our study showed that flies and water were reservoirs for all the four pathogens, campylobacter, ETEC-LT, shigella and salmonella. Flies from the village were carrying fewer enteropathogens, while water from the village was found to be more contaminated as compared to the city. Campylobacter and ETEC-LT were the most frequently isolated pathogens in both flies and water. Thus the incidence of diarrhoeal disease in children of developing countries may be decreased by providing plenty of safe drinking water, improving excreta disposal, toilet facilities and giving education in personal hygiene.

Early child health in Lahore, Pakistan: VIII. Microbiology.

The causative agents of acute diarrhoea were investigated in children under the age of five years from 1985-1991 in three socio-economically different areas in Lahore, Pakistan. The aim was to determine the frequencies of the most common enteropathogens in faeces. The total isolation rate was 73.4%; two thirds (53.5%) were of bacterial and one third (19.9%) of viral origin. ETEC-LT (23.4%), Rota virus (19.9%), EPEC (15%) and Campylobacter (12%) were the single most frequent pathogens in all age groups and areas of living. The positivity of Campylobacter increased from 1.6% to 12% after the change of isolation technique. Shigella was isolated significantly (p > 0.001) more in children over than under one year of age. The incidence of bacterial infections was high during all seasons, while in certain years Rota virus was relatively low in the summer compared to the cooler months. The prevalence of ETEC-LT diarrhoea was higher in the periurban slum as compared to the village and the urban slum. The study is the first of its kind in Pakistan, and the results are similar to other comparable studies. It is thus possible to establish a well functioning and reliable microbiological laboratory in developing countries in a setting with restricted trained personnel and material resources.

Frequency and enterotoxigenicity of Campylobacter jejuni and C. coli in domestic animals in Pakistan as compared to Sweden.

Domestic and wild animals have been considered to be the most common reservoirs of Campylobacter for human infections. This study has been conducted to establish the frequency and enterotoxigenicity of C. jejuni and C. coli in the stools of domestic animals in a developing versus a developed country. Faecal samples of 300 chickens and laying hens, 102 horses, 180 cows, 92 goats and sheep were collected from Pakistan and Sweden. The hippurate hydrolysis test and CHO-cell test were performed for species differentiation and enterotoxigenicity determination respectively. The pattern and sequence of frequency distribution of Campylobacter in animals in Pakistan and Sweden were similar, the main difference being a significantly higher frequency in Pakistani samples. C. jejuni was the dominant species from both countries and Pakistani strains were more enterotoxigenic than Swedish strains. We conclude that the spread of Campylobacter infection in developing countries originates from different sources in the neighbourhood, for example animals, and unless hygienic conditions improve no change can be expected.

Confirmation of assignment of the bovine K-casein locus by PCR.

The provision of a bovine gene map will allow the ready identification of genetic disease in cattle and will lead to the identification of the genetic loci responsible for quantitative traits of economic importance. An extension of the polymerase chain reaction to the identification of linkage in bovine-Chinese hamster cell hybrids has improved the speed and facility of the assignment of genes to linkage groups and thus makes it easier to achieve a bovine linkage map.

Enterotoxigenicity and frequency of Campylobacter jejuni, C. coli and C. laridis in human and animal stool isolates from different countries.

Campylobacter jejuni and C. coli strains were collected during three different years from adult patients with enterocolitis in Sweden (n = 372) from 49 patients in Kuwait, and Campylobacter strains from hens from Mexico, Pakistan and Sweden (n = 107) and Swedish pigs (n = 47). C. jejuni was the predominant species in human and hen isolates, and C. coli in pigs C. coli was significantly more common in human isolates from Sweden, and more common in hen isolates from Pakistan, than in hens from Sweden and Mexico. C. laridis was only isolated from pigs (17%) and was in no case enterotoxigenic. Both in human and hen isolates, C. jejuni strains were more enterotoxigenic than C. coli strains. C. jejuni strains from Swedish hens were less enterotoxigenic than those from Pakistan and Mexico (P less than 0.001), and strains from pigs were less enterotoxigenic than those from hens (P less than 0.001). We conclude that C. jejuni are more often enterotoxigenic and possibly more virulent than c. coli and C. laridis. The relative frequency of C. jejuni and C. coli in humans and animals differs from one country to another.