Female choice and manipulations of forceps size and symmetry in the earwig Forficula auricularia L

Nutrition influences the reproductive axis via alteration of gonadotrophin secretion. However, a link between nutrition and the secretion of GnRH, which drives the axis, has yet to be established. The aim of the present study was to measure the change in the concentrations of metabolic substances in the cerebrospinal fluid of adult male sheep offered a diet designed to maintain constant gonadotrophin secretion (Group M; n = 6), or a diet known to increase gonadotrophin secretion (Group M + L; n = 6). On days 1, 3 and 10 of the dietary treatments, cerebrospinal fluid and jugular blood were sampled and analysed for metabolic fuels (glucose, amino acids and free fatty acids) and metabolic hormones (insulin, insulin-like growth factor I, GH, prolactin, cortisol and the thyroid hormones). On day 11 of the dietary treatment, LH pulse frequency and mean FSH concentrations in Group M + L had increased relative to Group M and to day 0. Plasma concentrations of prolactin and insulin on days 3 and 10, and glucose and insulin-like growth factor I on day 10, were higher in Group M + L than in Group M, but only cerebrospinal fluid concentrations of insulin, glucose and certain amino acids were affected by the dietary treatments on days 3 and 10. Cerebrospinal fluid, but not plasma, concentrations of aspartate, tyrosine, cystine, phenylalanine and arginine on day 3, and glutamine, gamma-aminobutyric acid, threonine, alanine on days 3 and 10, were higher in Group M + L relative to Group M. On day 10, plasma and cerebrospinal fluid concentrations of arginine, phenylalaine, proline, tyrosine, methionine and phosphoserine, but only the plasma concentrations of linoleic acid, aspartate and serine, were higher in Group M + L than in Group M. Concentrations of triiodothyronine, thyroxine, and cortisol in plasma and cerebrospinal fluid were not affected. These results show that the nutritional stimulation of gonadotrophin secretion is accompanied primarily by fluctuations in plasma and cerebrospinal fluid concentrations of insulin and certain amino acids, which suggests that, when nutritional status is improved, insulin, amino acids and possibly glucose interact to modulate GnRH secretion.     

CD164, a novel sialomucin on CD34(+) and erythroid subsets, is located on human chromosome 6q21

CD164 is a novel 80- to 90-kD mucin-like molecule expressed by human CD34(+) hematopoietic progenitor cells. Our previous results suggest that this receptor may play a key role in hematopoiesis by facilitating the adhesion of CD34(+) cells to bone marrow stroma and by negatively regulating CD34(+) hematopoietic progenitor cell growth. These functional effects are mediated by at least two spatially distinct epitopes, defined by the monoclonal antibodies (MoAbs), 103B2/9E10 and 105A5. In this report, we show that these MoAbs, together with two other CD164 MoAbs, N6B6 and 67D2, show distinct patterns of reactivity when analyzed on hematopoietic cells from normal human bone marrow, umbilical cord blood, and peripheral blood. Flow cytometric analyses revealed that, on average, 63% to 82% of human bone marrow and 55% to 93% of cord blood CD34(+) cells are CD164(+), with expression of the 105A5 epitope being more variable than that of the other identified epitopes. Extensive multiparameter flow cytometric analyses were performed on cells expressing the 103B2/9E10 functional epitope. These analyses showed that the majority (>90%) of CD34(+) human bone marrow and cord blood cells that were CD38(lo/-) or that coexpressed AC133, CD90(Thy-1), CD117(c-kit), or CD135(FLT-3) were CD164(103B2/9E10)+. This CD164 epitope was generally detected on a significant proportion of CD34(+)CD71(lo/-) or CD34(+)CD33(lo/-) cells. In accord with our previous in vitro progenitor assay data, these phenotypes suggest that the CD164(103B2/9E10) epitope is expressed by a very primitive hematopoietic progenitor cell subset. It is of particular interest to note that the CD34(+)CD164(103B2/9E10)lo/- cells in bone marrow are mainly CD19(+) B-cell precursors, with the CD164(103B2/9E10) epitope subsequently appearing on CD34(lo/-)CD19(+) and CD34(lo/-)CD20(+) B cells in bone marrow, but being virtually absent from B cells in the peripheral blood. Further analyses of the CD34(lo/-)CD164(103B2/9E10)+ subsets indicated that one of the most prominent populations consists of maturing erythroid cells. The expression of the CD164(103B2/9E10) epitope precedes the appearance of the glycophorin C, glycophorin A, and band III erythroid lineage markers but is lost on terminal differentiation of the erythroid cells. Expression of this CD164(103B2/9E10) epitope is also found on developing myelomonocytic cells in bone marrow, being downregulated on mature neutrophils but maintained on monocytes in the peripheral blood. We have extended these studies further by identifying Pl artificial chromosome (PAC) clones containing the CD164 gene and have used these to localize the CD164 gene specifically to human chromosome 6q21.     

Positions and training of the indigenous health workforce

Laparoscopy and magnetic resonance imaging (MRI) are competetive tools in the diagnostic of non-palpable testis. Advantages and disadvantages of this methods will be demonstrate. 29 boys investigated for this indication with MRI. In case MRI failed to locate the testis laparoscopy was performed with a new miniaturized set of pediatric instruments (1.9 mm optic). The aim of laparoscopy was the identification of the spermatic duct and vessels and their topographic relation to the internal inguinal ring. All findings were verified by open surgical procedures. MRI revealed 10 inguinal and 7 abdominal testis. There was no false positive finding. In 12 boys MRI showed no testis. 4 cases were correct negative, 8 cases were false negative (32%). In these 8 MRI-negative patients laparoscopy revealed 7 inguinal and 1 abdominal testis. The optical quality of the mini-telescope was sufficient for a 100% correct diagnosis. Laparoscopy related complications did not occur. Laparoscopy proved to be a powerful low risk diagnostic method in non-palpable testis with high sensitivity and specifity (100% correct positive, 0% false negative). Therefore lapraroscopy is recommended as primary diagnostic access for this indication. In the same anesthesia a optimal therapy is possible. Nevertheless a positive MRI-finding locates the testis reliably, whereas a negative finding always needs further exploration because testis might have been missed.     

cDNA cloning and gene mapping of human homologs for Schizosaccharomyces pombe rad17, rad1, and hus1 and cloning of homologs from mouse, Caenorhabditis elegans, and Drosophila melanogaster

Mutations in DNA repair/cell cycle checkpoint genes can lead to the development of cancer. The cloning of human homologs of yeast DNA repair/cell cycle checkpoint genes should yield candidates for human tumor suppressor genes as well as identifying potential targets for cancer therapy. The Schizosaccharomyces pombe genes rad17, rad1, and hus1 have been identified as playing roles in DNA repair and cell cycle checkpoint control pathways. We have cloned the cDNA for the human homolog of S. pombe rad17, RAD17, which localizes to chromosomal location 5q13 by fluorescence in situ hybridization and radiation hybrid mapping; the cDNA for the human homolog of S. pombe rad1, RAD1, which maps to 5p14-p13.2; and the cDNA for the human homolog of S. pombe hus1, HUS1, which maps to 7p13-p12. The human gene loci have previously been identified as regions containing tumor suppressor genes. In addition, we report the cloning of the cDNAs for genes related to S. pombe rad17, rad9, rad1, and hus1 from mouse, Caenorhabditis elegans, and Drosophila melanogaster. These include Rad17 and Rad9 from D. melanogaster, hpr-17 and hpr-1 from C. elegans, and RAD1 and HUS1 from mouse. The identification of homologs of the S. pombe rad checkpoint genes from mammals, arthropods, and nematodes indicates that this cell cycle checkpoint pathway is conserved throughout eukaryotes.     

Clinical and pharmacokinetic characteristics of aminoglycoside nephrotoxicity in 201 critically ill patients

We studied 201 critically ill patients during 267 courses of gentamicin (139 courses) or tobramycin (128 courses) therapy. Clinical and pharmacokinetic data were obtained on 240 of 267 courses (120 courses each of gentamicin and tobramycin). Two judgments of nephrotoxicity and its cause were made independently in this study, using a clinical and a pharmacokinetic definition of nephrotoxicity. The two sets of criteria were generally in good agreement, as all but 10 of 41 patients who were judged nephrotoxic by pharmacokinetic criteria were independently judged nephrotoxic by the clinical definition. Groups of patients judged nontoxic did not differ from groups judged nephrotoxic in age, sex, weight, initial creatinine clearance, total dose given, duration of treatment, initial aminoglycoside trough serum levels, number of dosage adjustments, concurrent use of furosemide, or concurrent cephalosporins. Prior aminoglycosides (usually gentamicin) had been used more frequently in the nontoxic group (P less than 0.05). Two major conclusions of this study are at variance with those of previous investigators; (i) we found no clinical parameters of value in predicting nephrotoxicity in critically ill patients; and (ii) aminoglycoside serum concentrations, once in the therapeutic range, were of limited value in prevention of aminoglycoside nephrotoxicity in our patients.     

Some effects of limited feedback on performance and problem-solving strategy in a Logo microworld.

The effect of limiting the availability of immediate feedback in a Logo microworld was examined by observing children solve problems involving the reproduction of given rotations without the information provided by a rotating turtle. It was found that limiting the feedback in this way reduced the incidence of trial-and-error problem-solving strategies. There was also evidence that higher level problem-solving strategies, which took into account a wider range of problem features, were used to compensate for the restricted access to immediate feedback. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Architectures for exponentiation in GF(2m)

Several VLSI architectures for performing exponentiation in GF(2 ^m) are presented. Two approaches to the architecture design are taken. In the first, all intermediate products of the exponentiation are computed in a sequential fashion to minimize the silicon area. In the second approach, all values of raised to the 2^ei power, O⩽i⩽m-1, are precomputed and stored so that the intermediate product terms can be calculated in a parallel fashion. For the two approaches, both synchronous and asynchronous implementations are presented using standard and normal bases. The discussion emphasizes the design and performance tradeoffs incurred in developing such architectures     

Gold traps in 〈100〉 silicon-silicon dioxide interfaces

The effects of gold on the trapping states at the silicon-silicon dioxide interface have been studied. A theory is presented which allows the ‘static’ low frequency C-V characteristic of a MOS capacitor, with arbitrary interface trap distribution, to be determined. The quasi-static technique of Kuhn, which measures the displacement current response to a slowly varying linear voltage, is subsequently used to obtain experimental curves which are correlated with theory. It is found that at low temperatures (? 230°K) the technique resolves pronounced structure in the interfacial trap distribution that is not apparent at room temperature.To assess the effects of varying amounts of gold, various diffusion times at 900°C were used on n-type silicon wafers of (100) orientation. It was found that interface trap density increased with extended diffusion time, but the energy distribution remained essentially the same, exhibiting pronounced maxima at energies E_v + 0.36 eV and E_v + 0.63 eV. As well as producing peaks in the distribution, the gold diffusions resulted in an increase in interface state density by approximately a factor of 5 from the control devices.     

Poly(2-aminoadenylic acid): interaction with poly(uridylic acid)

Poly(2-aminoadenylic acid) forms both double and triple helices with poly(uridylic acid) [poly(U)]. The 2-amino group forms a third hydrogen bond, elevating the 2 leads to 1 transition temperature by 33 degrees C. The third strand, however, has about the same stability as poly(A)-2poly(U), as measured by Tm 3 leads to 2. This selective stabilization of the two-stranded helix results in a much greater resolution of the differnt thermal transitions than that observed in analogous polynucleotide systems. In contrast to other A, U systems 3 leads to 1 and 2 leads to 3 transitions are not observed under any conditions, and the triple helix always undergoes a 3 leads to 2 transition even at very high ionic strength. A 1:1 mixture of poly(2NH2A) and poly(U) exhibits no transient formation of 1:2 complex, unlike similar mixtures of poly(A) with poly(U) and poly(T). This difference is evidently due to a more rapid displacement reaction: [poly(2NH2A) + poly(2NH2A)-2poly(U) leads to 2 poly(2NH2A)-poly(U)] With poly(2NH2A) than with poly(A). We describe a method for establishing the combining ratios of polynucleotide complexes which used a computer to calculate the angles of intersection of mixing curves as explicit and continuous functions of the wavelength. The wavelength dispersions of the angles of intersection determine optimum wavelengths for establishing stoichiometry and can also provide reliable negative evidence that presumably plausible complexes are not formed. Analogous computer procedures have been developed to determine wavelengths which are selective for the formation of both 1:1 and 1:2 complexes. Infrared spectra of the 1:1 and 1:2 complexes resemble those of other A, U homoribopolynucleotide helices in having two and three strong bands, respectively, in the region of carbonyl stretching vibrations. CD spectra of the two complexes are unusual in having negative first extrema of moderate intensity. We attribute these extrema to intrastrand interactions of strong, well-resolved transitions at 278 nm (B2u) of the 2-aminoadenine residues. The CD spectra are correlated with those of other polynucleotide helices.