Diagnosis of malaria--an overview

PURPOSE: To examine the anterior optic nerve vasomotor effects of nonselective and relatively beta-1-selective beta-adrenergic antagonists in rabbits, because different influences on optic nerve blood flow with these medications have been suggested. METHODS: After topical therapy for 30 days with either timolol maleate 0.5% (six rabbits), betaxolol hydrochloride 0.5% (six rabbits), or placebo (two rabbits), the microvasculature of the optic nerve was examined with an intraluminal microvascular corrosion casting technique. The investigators were masked to both the medication group and the treated eye. The constriction, in percent of the downstream vessel caliber, was measured at the vascular branching point of arterioles supplying the anterior optic nerve. An average constriction was calculated and compared between the medication groups and between the treated and the contralateral, untreated eyes. RESULTS: Constriction values from a total of 218 arterioles supplying the anterior optic nerve were obtained for the 14 rabbits. The means of the average constriction on the treated side were comparable between the groups treated with timolol maleate, betaxolol hydrochloride, and placebo (one-way analysis of variance, P = .64), as well as between the treated and untreated eyes (two-tailed t-test for paired variables, P = .68 for timolol maleate and P = .42 for betaxolol hydrochloride). The statistical power to find a difference of 5% or more average constriction was at least 90%. CONCLUSIONS: Both relatively selective and nonselective beta-adrenergic antagonists produce no observable optic nerve vasomotor effects in the rabbit eye.     

Identification of a graft versus host disease-associated human minor histocompatibility antigen

Minor histocompatibility antigen disparities between human leukocyte antigen (HLA)-matched bone marrow donors and recipients are a major risk factor for graft versus host disease (GVHD). An HLA-A2.1-restricted cytotoxic T cell clone that recognized the minor histocompatibility antigen HA-2 was previously isolated from a patient with severe GVHD after HLA-identical bone marrow transplantation. The HLA-A2.1-bound peptide representing HA-2 has now been identified. This peptide appears to originate from a member of the non-filament-forming class I myosin family. Because HA-2 has a phenotype frequency of 95 percent in the HLA-A2.1-positive population, it is a candidate for immunotherapeutic intervention in bone marrow transplantation.     

A detailed linkage map of rainbow trout produced using doubled haploids

We report the first detailed genetic linkage map of rainbow trout (Oncorhynchus mykiss). The segregation analysis was performed using 76 doubled haploid rainbow trout produced by androgenesis from a hybrid between the "OSU" and "Arlee" androgenetically derived homozygous lines. Four hundred and seventy-six markers segregated into 31 major linkage groups and 11 small groups (< 5 markers/group). The minimum genome size is estimated to be 2627.5 cM in length. The sex-determining locus segregated to a distal position on one of the linkage groups. We analyzed the chromosomal distribution of three classes of markers: (1) amplified fragment length polymorphisms, (2) variable number of tandem repeats, and (3) markers obtained using probes homologous to the 5' or 3' end of salmonid-specific small interspersed nuclear elements. Many of the first class of markers were clustered in regions that appear to correspond to centromeres. The second class of markers were more telomeric in distribution, and the third class were intermediate. Tetrasomic inheritance, apparently related to the tetraploid ancestry of salmonid fishes, was detected at one simple sequence repeat locus and suggested by the presence of one extremely large linkage group that appeared to consist of two smaller groups linked at their tips. The double haploid rainbow trout lines and linkage map present a foundation for further genomic studies.     

Intravenous administration of L-kynurenine to rhesus monkeys: effect on quinolinate and kynurenate levels in serum and cerebrospinal fluid

The effects of 2-buten-4-olide (2-B40), an endogenous feeding suppressant, on the secretion of luteinizing hormone (LH) were studied in ovariectomized rats. Intraperitoneal (ip) administration of 2-B40: adult female ovariectomized Wistar rats were given daily ip injections of solution containing 2-B40 at 0, 50 or 100 mg/kg body wt for 14 days. This ip treatment with 2-B40 significantly decreased the mean LH concentration and pulse frequency of LH. Intravenous (iv) administration of 2-B40: a solution of 2-B40 (50 or 100 mg/kg body wt) was slowly injected through an intra-atrium catheter and blood samples were taken every 6 min for 2 h. This iv treatment significantly suppressed the LH pulse frequency but had no significant effect on the LH amplitude or mean LH. Injection of 2-B40 into the third cerebroventricle: the injection of 2-B40 into the third cerebroventricle of freely moving rats decreased the mean LH concentration and the frequency and amplitude of LH pulses. Third cerebroventricle injection of a corticotropin-releasing factor (CRF) receptor antagonist before third cerebroventricle injection of 2-B40: the specific CRF receptor antagonist alpha-helical-CRF (9-41) was injected into the third cerebroventricle of ovariectomized rats before injection of 2-B40. Administration of 2-B40 into the third cerebroventricle significantly decreased the mean LH, concentration and pulse frequency. Third cerebroventricle injection of the CRF antagonist at 50 micrograms/rat and then 2-B40 also resulted in significant suppression of the mean LH concentration and pulse frequency.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hemostatic profile in nephrotic syndrome

OBJECTIVE: To evaluate the coagulation profile and its relation to steroid therapy, and the frequency of thromboembolic complications and its correlation with coagulation parameters in nephrotic syndrome (NS). SETTING: Hospital based. SUBJECTS AND METHODS: Forty children with NS were subdivided into four groups, namely, fresh cases, steroid dependent, remission after therapy and steroid resistant. An equal number of age and sex matched children served as controls. In all the study and control subjects, detailed clinical examination, liver function tests, renal function tests and detailed coagulation profile were done. Evaluation of renal veins and inferior vena cava for the presence of thrombosis was also done by abdominal ultrasonography. RESULTS: Thrombocytosis was detected in 57.5% and the degree of thrombocytosis was directly related to the amount of proteinuria. The mean prothrombin and thrombin times were within normal range in the study children. The activated partial thromboplastine time (APTT) was prolonged in six cases (15%) and three out of these six children had thromboembolic complications. Antithrombin-III level was significantly lower (p < 0.001) whereas protein C and S were significantly elevated (p < 0.001) as compared to controls. The levels became normal with remission of the disease. Steroid therapy significantly increased the levels of proteins C, protein S. AT-III and fibrinogen as compared to controls. Thromboembolic complications were seen in 3 cases (7.6%) and were associated with very low levels of AT-III and protein C and all three had serum albumin below 2 g/dl. CONCLUSIONS: The importance of coagulation profile in nephrotic syndrome is highlighted and a high index of suspicion for thromboembolic complications is warranted in patients with thrombocytosis, hyper fibrinogenemia, prolonged APTT and in children with low levels of AT-III, protein C and protein S.     

In vitro maintenance of Leishmania amastigotes directly from lesions: advantages and limitations

Leishmania amazonensis (MHOM/BR/77/LTB0016) amastigotes were obtained from mouse cutaneous lesions and maintained in vitro for 48 hr at pH 4.6, 33 C. These organisms were reproducing, capable of transformation to promastigotes, and did not display the promastigote-specific antigen, GP46. In contrast, 97% of the organisms maintained for 24 hr at 31 C, pH 7.3, were positive for GP46. Thus, short-term cultivation of this L. amazonensis strain under appropriate conditions can provide a high yield of amastigotes for various in vivo and in vitro studies. However, the possible interference of host immunoglobin on the surface of these amastigotes needs to be considered because fluorescent-labeled anti-mouse immunoglobulin was detected on 16% of lesion-derived amastigotes even after 114 hr of cultivation.     

Comparison of binding parameters of sigma 1 and sigma 2 binding sites in rat and guinea pig brain membranes: novel subtype-selective trishomocubanes

Comparisons of binding parameters of [3H](+)-pentazocine and [3H]1,3-di-o-tolylguanidine (DTG) at sigma binding sites in guinea pig and rat brain membranes demonstrated that [3H](+)-pentazocine binds to a single high-affinity site, whereas [3H]DTG binds to two high-affinity sites in both species. The Kd values of the radioligands were similar in both types of membranes. However, the density of sigma 1 sites in guinea pig was significantly higher than that of rat. Novel trishomocubanes were tested for their affinities at sigma 1 and sigma 2 binding sites in guinea pig brain membranes using [3H](+)-pentazocine and [3H]DTG as the radioligands. N-(4-Phenylbutyl)-3-hydroxy-4- azahexacyclo[5.4.1.0(2,6).0(3,10).0(5,9).0(8,11)]dodecane (ANSTO-14) showed the highest affinity for the sigma 1 site (Ki = 9.4 nM) and 19-fold sigma 1/sigma 2 selectivity, as a result of increasing the alkyl chain between the cubane moiety and the aromatic ring. N-(3'-Fluorophenyl)methyl- 3-hydroxy-4-azahexacyclo[5.4.1.0(2,6).0(3,10).0(5,9).0(8,11]dodeca ne (ANSTO-19), displayed the highest affinity for sigma 2 sites (Ki = 19.6 nM) and 8-fold sigma 2/sigma 1 selectivity due to a fluoro substitution in the meta position of the aromatic ring. These represent structurally novel lead compounds, especially for the development of selective sigma 2 receptor ligands.