The effects of hedgehog ligand neutralising antibody 5E1 in a mouse model of endometriosis.

OBJECTIVE: Endometriosis is a common and painful condition characterised by the formation of endometrial lesions within the peritoneal cavity. Previous studies have suggested a role for hedgehog signalling in the pathogenesis of endometriosis. We investigated the role of hedgehog signalling in the establishment of endometriosis lesions using 5E1, a hedgehog ligand neutralising antibody, and a mouse model of endometriosis. To mimic the initiation of endometriosis by retrograde menstruation, which is believed to occur in humans, donor mice underwent an artificial menstruation protocol. Fragments of menstrual endometrium were injected into the peritoneal cavity of estrogen primed recipients. Recipients received twice weekly injections of 5E1 or an isotype matched control antibody for three weeks. Lesions were collected and analysed for markers of epithelium, proliferation and apoptosis by immunofluorescence microscopy. RESULTS: Treatment with 5E1 reduced the number of lesions found on the mesentery. No significant changes were found in the size of lesions, abundance of endometrial epithelial cells, proliferation or apoptosis.

Conservation of genetic linkage with map expansion in distantly related crosses of Agaricus bisporus.

A previous map of the genome of a hybrid strain which had European parents belonging to the secondarily homothallic fungus Agaricus bisporus var. bisporus appeared to be unusually compact, with a particularly recombophobic segment in the central part of chromosome I. A new map of this segment was constructed based on allelic segregations among 103 homokaryotic offspring of an A. bisporus hybrid between a European parent of the var. bisporus and a Californian parent of the heterothallic var. burnettii. Markers completely linked on the previous map were distributed along 28 cM in the new map. These results suggest that the greater recombination rate could be correlated with the outbreeding behaviour of the var. burnettii.

Phosphaturic effect of L-NMMA in the presence of parathyroid hormone.

The objective of this study was to examine the effect of NG-monomethyl-L-arginine (L-NMMA) on phosphate excretion in the presence and absence of parathyroid hormone (PTH). Renal clearances were obtained before and during infusion of L-NMMA (15 mg/kg bolus and 500 micrograms.kg-1.min-1 infusion) in Sprague-Dawley rats with intact parathyroid glands (n = 6), in thyroparathyroidectomized (TPTX) rats receiving a constant infusion of PTH-(1-34) (0.01-0.03 U.kg-1.min-1) (n = 11) throughout the experiment, or in TPTX rats, that received an acute infusion of PTH-(1-34) (33 U/kg bolus and 1 U.kg-1.min-1 infusion) after L-NMMA infusion alone (n = 7). In rats with intact parathyroid glands, L-NMMA increased the fractional excretions of phosphate (FEPi) and sodium (FENa) and mean arterial pressure (MAP) (delta 8.6 +/- 1.5%, delta 0.62 +/- 0.1%, and delta 26.7 +/- 4.9 mmHg, respectively; P < 0.05). In TPTX rats receiving a constant infusion of PTH, L-NMMA again increased FEPi, FENa, and MAP (delta 9.5 +/- 3.6%, delta 1.1 +/- 0.4%, and delta 28.4 +/- 4.5 mmHg, respectively; P < 0.05). However, in TPTX rats, L-NMMA alone did not increase FEPi (delta 0.9 +/- 0.3%), whereas the subsequent infusion of PTH with L-NMMA increased FEPi (delta 15.6 +/- 3.1%; P < 0.05). In an additional group of intact and TPTX rats, the fractional excretion of lithium (FELi) was measured as an index of proximal reabsorption. L-NMMA increased FELi in intact rats (delta 13.2 +/- 2.6%; P < 0.05), but not in TPTX rats (delta 4.2 +/- 3.3%). In conclusion, L-NMMA increases phosphate excretion in association with increases in MAP and FENa, and this phosphaturic effect is dependent on the presence of PTH.

Localization of the Mating Type Gene in Agaricus bisporus.

The cultivated mushroom Agaricus bisporus is secondarily homothallic. Most basidia produce two basidiospores, each of which receives two of the four postmeiotic nuclei. Usually, the two packaged nuclei carry compatible mating types. Previous studies suggested that there may be only a single mating type locus in A. bisporus. In this study, we determined whether the mating type segregated as a single Mendelian determinant in a cross marked with 64 segregating molecular markers. To score mating types, each of the 52 homokaryotic offspring from this cross was paired with each of the two progenitor homokaryons. Compatible matings were identified by the formation of genetically stable heterokaryons which were verified by assay of restriction fragment length polymorphisms (RFLPs). Data for screening mycelial interactions on petri plates as well as fruit body formation were compared with the RFLP results. Mating types of 43 of the 52 homokaryotic offspring were determined on the basis of RFLP analysis. Our results indicate (i) there is a segregating mating type gene in A. bisporus, (ii) this mating type gene is on the largest linkage group (chromosome I), (iii) mycelial interactions on petri plates were associated with heterokaryon formation under selected conditions, (iv) fruit body formation was dependent upon the mating type gene, and (v) compatible mating types may not always be sufficient for fruiting.

Meiotic behavior and linkage relationships in the secondarily homothallic fungus Agaricus bisporus.

This study followed the transmission of 64 segregating genetic markers to 52 haploid offspring, obtained from both homokaryotic and heterokaryotic meiospores, of a cross (AG 93b) of Agaricus bisporus, the commonly cultivated "button mushroom." The electrophoretic karyotypes of the AG 93b component nuclei were determined concurrently (n = 13). Eleven distinct linkage groups were identified by two-point analysis. DNA-DNA hybridization showed that nine of these corresponded to unique chromosome-sized DNAs. Two other chromosomal DNAs were marked with nonsegregating markers, including the rDNA repeat. Two remaining chromosomes remained unmarked but hybridized to repeated-sequence probes. Cross 93b had an essentially conventional meiosis in which both independent assortment and joint segregation of markers occurred, but in which crossing over was infrequent over much of the mapped genome. The 48 homokaryotic spore-offspring had overall crossover frequencies that were similar to, but possibly slightly less than, those of three homokaryon constituents of heterokaryotic spore-offspring. These daa provide support for our earlier cytogenetic model of sporogenesis in A. bisporus, that explains why heterokaryotic spore-offspring usually appear to exhibit no recombination. No evidence favoring an alternative, mitotic model of sporogenesis was found. The resulting genetic map appears to survey the genome extensively and for the first time permits localization of loci determining economically important traits in this fungal crop species. Large differences in the vigor of homokaryotic offspring were correlated with the inheritance of certain chromosome segments and were also often associated with significant departures from Mendelian segregation ratios.

Acute renal denervation decreases tubular phosphate reabsorption.

Acute renal denervation (DNX) has been reported to increase urinary phosphate (Pi) excretion in rats with intact parathyroid glands and also in rats which were thyroparathyroidectomized (TPTX). The present study was performed to determine the effects of acute renal denervation on the tubular transport of Pi in rats in the absence of parathyroid hormone (PTH) and in rats with constant PTH levels. In TPTX rats, the reabsorbed Pi normalized for the glomerular filtration rate (Reab Pi/GFR) was 2.38 +/- 0.16 mumol/ml in the DNX kidney compared to 2.56 +/- 0.16 mumol/ml (p < 0.05) in the contralateral innervated (INN) kidney at endogenous plasma phosphate levels (n = 6). The lower values for the Reab Pi/GFR in the DNX kidney persisted at elevated plasma phosphate concentrations during phosphate infusions. Infusion of PTH resulted in markedly lower Reab Pi/GFR values in the innervated kidney (1.47 +/- 0.21 mumol/ml) at endogenous plasma phosphate levels than in the vehicle-infused group. Furthermore, the Reab Pi/GFR in the DNX kidney was decreased (1.21 +/- 0.14 mumol/ml, n = 6) compared to the contralateral INN kidney. These studies demonstrate that acute renal DNX decreases the tubular transport of Pi both in the absence and in the presence of constant PTH levels.

Yellow Blotch of Pleurotus ostreatus.

Yellow blotch disease of the oyster mushroom (Pleurotus ostreatus) was first observed in a commercial mushroom farm in California in 1983. The disease, caused by Pseudomonas agarici, is characterized by primordia, with yellow droplets on their surface, which become stunted, yellow to orange, and deformed as they mature.