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Biomedical subjects

R Sheriff

Publications and source records attributed to R Sheriff.

8 recordsLinked to original sources
PubMed2004

Integrating genetics and genomics to identify new leads for the control of Eimeria spp.

Eimerian parasites display a biologically interesting range of phenotypic variation. In addition to a wide spectrum of drug-resistance phenotypes that are expressed similarly by many other parasites, the Eimeria spp. present some unique phenotypes. For example, unique lines of Eimeria spp. include those selected for growth in the chorioallantoic membrane of the embryonating hens egg or for faster growth (precocious development) in the mature host. The many laboratory-derived egg-adapted or precocious lines also share a phenotype of a marked attenuation of virulence, the basis of which is different as a consequence of the in ovo or in vivo selection procedures used. Of current interest is the fact that some wild-type populations of Eimeria maxima are characterized by an ability to induce protective immunity that is strain-specific. The molecular basis of phenotypes that define Eimeria spp. is now increasingly amenable to investigation, both through technical improvements in genetic linkage studies and the availability of a comprehensive genome sequence for the caecal parasite E. tenella. The most exciting phenotype in the context of vaccination and the development of new vaccines is the trait of strain-specific immunity associated with E. maxima. Recent work in this laboratory has shown that infection of two inbred lines of White Leghorn chickens with the W strain of E. maxima leads to complete protection to challenge with the homologous parasite, but to complete escape of the heterologous H strain, i.e. the W strain induces an exquisitely strain-specific protective immune response with respect to the H strain. This dichotomy of survival in the face of immune-mediated killing has been examined further and, notably, mating between a drug-resistant W strain and a drug-sensitive H strain leads to recombination between the genetic loci responsible for the specificity of protective immunity and resistance to the anticoccidial drug robenidine. Such a finding opens the way forward for genetic mapping of the loci responsible for the induction of protective immunity and integration with the genome sequencing efforts.

Animals↗
PubMed2000

Clinical features of systemic lupus erythematosus in Sri Lankan patients: results from a lupus clinic.

OBJECTIVES: To find the common clinical features, pattern of visceral involvement, treatment received and outcome in patients diagnosed as having systemic lupus erythematosus (SLE) on American Rheumatological Association (ARA) criteria. SETTING: Clinic for patients referred or admitted to the University Medical Unit, National Hospital of Sri Lanka, Colombo, with diagnosed or suspected SLE. DESIGN AND METHODS: A prospective descriptive study. Clinical features of patients collected at time of registration in the clinic were maintained in a database. Patients were followed up prospectively and changes recorded. Data were analysed after 3 years of follow up. RESULTS: Of the 111 patients registered during this period, 96 (86%) were clinically diagnosed as having SLE. Of these, 77 patients (80%) satisfied ARA criteria for diagnosis of SLE. 72 were females (93%). The mean age of patients who satisfied the ARA criteria was 32 years (range 11 to 58), and the mean duration of disease 7 years (range 1 to 15). The commonest presentation was with mucocutaneous features (98%) and alopecia in 87%. Systemic features were found in 92% of patients. 67 (87%) of patients had visceral involvement with 60 (78%) having it at time of diagnosis. 53 (69%) had renal, 42 (54%) haematological, 33 (42%) neurological, 12 (16%) cardiac and 8 patients pulmonary involvement. Five patients died during the 3-year follow up and 2 developed chronic renal failure. Three patients underwent successful pregnancy after diagnosis of SLE. CONCLUSIONS: Our study confirmed the wide variability of clinical features seen in SLE. Alopecia and visceral involvement were common in Sri Lankan patients.

Adolescent↗
PubMed2000

Pregnancy following renal transplantation in Sri Lanka.

OBJECTIVE: To assess the outcome and complications of pregnancy following renal transplantation in Sri Lanka. METHODS: Ten pregnancies following transplantation managed between January 1993 and July 1999 by the University Obstetrics and Gynaecology Unit, De Soysa Hospital for Women, Colombo were reviewed. RESULTS: Five women had planned pregnancy with an average duration from transplantation to conception of 2.3 (+/- 0.2) years; five had an unplanned pregnancy within 12 months of transplantation. All were treated with immunosuppressives, with none developing rejection. In the planned pregnancy group, 3 developed pregnancy induced hypertension and 3 impaired glucose tolerance. All delivered mature healthy babies with an average birth weight of 2.6 (+/- 0.3) kg. In the unplanned group, 1 developed cholestatic jaundice and delivered a growth retarded baby at 36 weeks. Another developed severe pulmonary oedema at 34 weeks (due to a past myocardial infarction) resulting in a fresh stillbirth. Two others has mid-trimester foetal deaths complicating severe diabetes mellitus. The conception at 3 months after transplantation developed diabetes mellitus and pregnancy induced hypertension, and delivered a live growth retarded baby. None had deterioration of renal function. CONCLUSION: Although a successful outcome is possible with stringent pre-pregnancy selection, maternal morbidity and foetal wastage can be high in those without.

Adult↗
PubMed1999

A new monospecific ovine Fab fragment antivenom for treatment of envenoming by the Sri Lankan Russell's viper (Daboia Russelii Russelii): a preliminary dose-finding and pharmacokinetic study.

Russell's viper is the most important cause of life-threatening snake bite and acute renal failure in Sri Lanka. Only equine polyspecific antivenoms imported from India are available. They have not proved effective clinically or in clearing venom antigenemia and they frequently cause reactions. In an attempt to reduce mortality and morbidity, a new monospecific ovine Fab fragment antivenom (PolongaTab; Therapeutic Antibodies, Inc., London, United Kingdom) was raised against Sri Lankan Russell's viper venom. In a preliminary dose-finding study in 35 patients, an initial dose of 3-4 g restored blood coagulability permanently and stopped systemic bleeding, even in severely envenomed patients. Venom antigenemia disappeared within 1 hr of antivenom treatment but recurred, probably as a result of continued absorption of venom from the site of the bite, after the rapid clearance of therapeutic antibody. Twelve patients (34%) experienced early reactions that were usually mild and always responded to epinephrine.

Adolescent↗
PubMed1995

The quality of function of renal allografts is associated with donor age.

The quality of renal allograft function was assessed by prospective measurement of creatinine clearance at 1 year (n = 197) and at 3 years (n = 115) after cadaveric renal transplantation in a cohort of 268 patients treated with triple therapy immunosuppression. Donor age (P < 0.0012) and recipient age (P < 0.01) were independently associated with creatinine clearance both at 1 and at 3 years. In patients with donor age above 50 years and recipient age above 45 years, the mean creatinine clearance was 32.7 (SD 10.4) ml/min (n = 27). When the donor age was below 30 years and recipient age below 45 years, the mean creatinine clearance was 55.6 (SD 14.4) ml/min (n = 47, P < 0.001). However, in these patients there was no significant association between graft function and many of the factors known to influence graft survival, such as HLA matching, sensitisation of the recipient, and the occurrence of rejection. In conclusion, the quality of renal allograft function declined with increasing donor and recipient age in our patients, whilst immunological factors were not significantly associated with function in surviving grafts.

Adolescent↗
PubMedDate not supplied

Integrating centralized and decentralized organization structures: an education and development model.

Organization change efforts have led to critically examining the structure of education and development departments within hospitals. This qualitative study evaluated an education and development model in an academic health sciences center. The model combines centralization and decentralization. The study results can be used by staff development educators and administrators when organization structure is questioned. This particular model maximizes the benefits and minimizes the limitations of centralized and decentralized structures.

Academic Medical Centers↗