Polymerase chain reaction detection of Leishmania DNA in skin biopsy samples in Sri Lanka where the causative agent of cutaneous leishmaniasis is Leishmania donovani

Leishmania donovani is the known causative agent of both cutaneous (CL) and visceral leishmaniasis in Sri Lanka. CL is considered to be under-reported partly due to relatively poor sensitivity and specificity of microscopic diagnosis. We compared robustness of three previously described polymerase chain reaction (PCR) based methods to detectLeishmania DNA in 38 punch biopsy samples from patients presented with suspected lesions in 2010. Both, Leishmaniagenus-specific JW11/JW12 KDNA and LITSR/L5.8S internal transcribed spacer (ITS)1 PCR assays detected 92% (35/38) of the samples whereas a KDNA assay specific forL. donovani (LdF/LdR) detected only 71% (27/38) of samples. All positive samples showed a L. donovani banding pattern upon HaeIII ITS1 PCR-restriction fragment length polymorphism analysis. PCR assay specificity was evaluated in samples containing Mycobacterium tuberculosis, Mycobacterium leprae, and human DNA, and there was no cross-amplification in JW11/JW12 and LITSR/L5.8S PCR assays. The LdF/LdR PCR assay did not amplify M. leprae or human DNA although 500 bp and 700 bp bands were observed in M. tuberculosis samples. In conclusion, it was successfully shown in this study that it is possible to diagnose Sri Lankan CL with high accuracy, to genus and species identification, using Leishmania DNA PCR assays.     

KINETIC-MICROARCHITECTURAL CORRELATIONS IN THE BONE MARROW OF THE MOUSE

Transverse histologic sections of bone marrow obtained from mice that were sacrificed by perfusion fixation at intervals following tritiated thymidine injection were studied by means of radioautography. A kinetic gradient was demonstrated across the marrow section, with the highest proliferative rate in the subendosteal region. Megakaryocytes were shown to originate from the rapidly proliferating subendosteal cells. The immediate proliferating precursors of mature granulocytes were slowly proliferating cells found predominantly in the central region of the marrow. It was concluded that in the steady state there must be a migration of cells from the subendosteal region to the central region with concomitant growth retardation of the migrating cells.     

Differences in steroidogenesis by the subcellular fractions of adrenocortical special zone and cortex proper of the female possum (Trichosurus vulpecula)

Steroidogenesis by subcellular fractions of adrenal cortex proper (C.P.) and special zone (S.Z.) of female possum (Trichosurus vulpecula) was studied. Mitochondrial, microsomal and cytosol cell fractions were incubated with appropriate substrates in the presence of an NADPH-generating system. The major products formed from [3H]progesterone and [3H]17 alpha-hydroxyprogesterone by the microsomal fraction of the C.P. were 11-deoxycortisol and 11-deoxycorticosterone and 3 alpha (beta)-hydroxy-5 alpha-androstan-17-one by the S.Z. The mitochondrial fraction converted [3H]11-deoxycortisol to cortisol in yields twenty times higher by the C.P. than by the S.Z. and to 17 alpha, 20 beta,21-trihydroxy-4-pregn-3-one thirty times higher by the S.Z. The conversion of [3H]androstenedione to 11 beta-hydroxyandrostenedione by the C.P. was approximately double that of the S.Z., while 18-hydroxyandrostenedione (tentatively identified) formed the highest yield in both zones. Incubation of the same substrates with cytosol formed two 5 beta-pregnane and two 5 beta-androstane derivatives in total yields less than 5% by C.P. and greater than 60% by S.Z. Aromatase activity, estimated by the release of [3H2O] from [1 beta 3H]testosterone, in the adrenals of 8 possums, was in each experiment negligibly low. Determination of total enzyme activities in the two zones revealed that 11 beta, 18 and 21-hydroxylases were higher in the C.P., while 17 alpha-hydroxylase was higher in the S.Z. Similar results were obtained when the rates of formation of hydroxylated products were estimated in the presence of saturating amounts of substrates. Active 5 alpha- and 5 beta-reductases, C17-20-lyase and 3 alpha (beta) and 20 beta-hydroxysteroid dehydrogenases were found almost exclusively in the S.Z. We conclude that the S.Z. at lower levels of activity than the C.P. could contribute to the basal secretion of corticosteroids. In addition, the S.Z. has a high capacity to form C19 steroids and 5 alpha- and 5 beta-reduced steroids. The possible role of the S.Z. in possum is discussed.     

Survey of treatment of primary breast cancer in Great Britain.

A postal survey of current management of breast cancer among surgeons in Great Britain was carried out. The results showed that there is no consensus among surgeons about the treatment of primary breast cancer. Many different types of primary surgery are practised, and patterns of referral for postoperative radiotherapy vary widely. Adjuvant systemic treatment is given often by some surgeons and not at all by others. Few patients are entered into controlled randomised trials.     

Displacement sensors in the honeybee pollen basket

The mechanical importance of different groups of corbicular setae to the formation and maintenance of the pollen load was established through ablation experiments. The neurophysiological characteristics of corbicular setae were investigated and it was found that there are three types of response to mechanical displacement of individual setae. At least some of the anterior corbicular setae behave as linear displacement sensors and are capable of measuring the size of the forming pollen load during foraging.     

PCSK9 SNP rs11591147 is associated with low cholesterol levels but not with cognitive performance or noncardiovascular clinical events in an elderly population

Proprotein convertase subtilisin-like/kexin type 9 (PCSK9) is a protein involved in LDL-cholesterol metabolism. The single-nucleotide polymorphism (SNP) rs11591147 has been associated with lower LDL-cholesterol and a lower risk of coronary heart disease. Because PCSK9 has high affinity to the LDL receptor, inhibiting PCSK9 is a testable therapeutic target for lipid-lowering therapy. Currently, several approaches to inhibit PCSK9 are under development, but it is unknown what the effects of those inhibitors will be on cognition or noncardiovascular clinical events. In this study, we assessed the association between rs11591147 and cognitive performance, activities of daily living (ADL), and noncardiovascular clinical events within 5,777 participants of the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER). Rs11591147 was associated with 10% to 16% lower LDL cholesterol levels (P = 3.62 × 10⁻¹²), but was not associated with cognitive performance, ADL, or noncardiovascular clinical events in the PROSPER study. Our findings suggest that lower cholesterol levels due to genetic variation in the PCSK9 gene are not associated with cognitive performance, functional status, or noncardiovascular clinical events.