Khalid Al-Habsi

Serological evidence of caprine arthritis–encephalitis virus (CAEV) infection in indigenous goats in the Sultanate of Oman

Caprine arthritis encephalitis (CAE) is a chronic debilitating disease of goats caused by a lentivirus responsible for economic losses as a result of a drop in milk production and weight loss. The objective of the study was to determine if indigenous goats from five different regions in the Sultanate of Oman exhibit serological evidence of exposure to CAEV using a competitive-inhibition ELISA technique. Blood samples were collected from slaughtered goats (N = 1,110) and from the National Serum Bank (n = 528). In total, 83 (5.1%) of screened samples were classed as seropositive. The results provide the first serological evidence for the presence of CAEV in Oman.

The effect of low levels of dietary cobalt on the chemiluminescence response of polymorphonuclear leukocytes of goats.

Twenty ten-week-old newly weaned male Batinah goats were randomly assigned to a control (n=10) and a treated (n=10) group and were fed a diet containing 0.1mg/kg DM cobalt (Co). Goats in the treated group received bi-monthly subcutaneous injections of 2000 microg of hydroxycobalamin. The phagocytic function of the polymorphonuclear leukocytes (PMN) were tested using a luminol-dependent chemiluminescence assay with opsonized zymosan as the phagocytic target. One month after the onset of the experiment PMN from the control group exhibited a significantly (p<0.05) lower CL response, which continued for the second month. The results of the present study demonstrated that low levels of dietary cobalt leads to an early impairment of phagocytic function. This may at least in part, be an explanation as to why at the field level in Oman young goats fed diets containing low levels of Co appear to be more susceptible to infections.

Rituximab leads to long remissions in patients with chronic immune thrombocytopenia

OBJECTIVES To assess the response rate and duration of response in patients with chronic immune thrombocytopenia (ITP) receiving rituximab. METHODS We retrospectively analyzed 32 consecutive patients with chronic ITP who were treated in two tertiary centers in Oman. Response assessment was based on the American Society of Hematology criteria. RESULTS Nineteen patients (59%) had an initial response. However, six of the 19 patients lost their response leaving 13 patients with long-lasting remissions. The median age at diagnosis was 25 years (range 14-58). The median time from diagnosis to rituximab therapy was 21 months. The median follow-up after starting rituximab was 26 months. The overall cumulative response rate was 59% (complete response 44%, partial response 15%) and the median time to respond was 30 days with a response rate of 44% at four weeks. In all responders, the cumulative rate of loss of response was 32% with a median time to lose response of 54 months. CONCLUSIONS The use of rituximab in ITP achieves high response rate and long remission duration. Our study was limited by the small sample size and further larger prospective studies are recommended.

Comparative chemiluminescence of neonatal and adult ovine polymorphonuclear leukocytes

Polymorphonuclear leukocytes (PMN) serve on the first line of the immunological defense of ruminants. However, despite the high morbidity and mortality of neonatal lambs to a wide range of infections there have been no definitive studies undertaken to ascertain whether there might be functional differences in PMN from neonatal lambs when compared to those from adult sheep. To determine whether there were differences in the oxidative respiratory burst of PMN, luminol-dependent chemiluminescence (CL) measurements were made of PMN from lambs at 1 week, 1, 2 and 3 months of age and at the same time from their respective dams. PMN isolated from lambs exhibited significantly lower levels of CL until 2 months of age. At 3 months of age the PMN produced levels of CL equal to that of their dams. As CL mirrors the ability of PMN to efficiently phagocytize and kill pathogens the present findings would suggest that PMN of neonatal lambs during the first 2 months are likely less capable of defending them from pathogenic organisms.