Thehermit transposable element of the Australian sheep blowfly,Lucilia cuprina, belongs to thehAT family of transposable elements

We report the cloning ofhermit, a member of thehAT family of transposable elements from the genome of the Australian sheep blowfly,Lucilia cuprina. Hermit is 2716 bp long and is 49% homologous to the autonomoushobo element,HFL1, at the nucleic acid level.Hermit has 15 bp terminal inverted repeats that share 10 bp with the terminal inverted repeats ofHFL1. Conceptual translation reveals a 583 residue open reading frame (ORF) that is 64% similar and 42% identical to theHFL1 ORF. However, the sequence of thehermit element contains two frameshifts within the putative ORF, indication thathermit is an inactive element. Analysis ofL. cuprina strains from within and outside Australia suggested thathermit is present as a single copy in all the genomes analysed.     

An Essential Role for CD44 Variant Isoforms in Epidermal Langerhans Cell and Blood Dendritic Cell Function

Upon antigen contact, epidermal Langerhans cells (LC) and dendritic cells (DC) leave peripheral organs and home to lymph nodes via the afferent lymphatic vessels and then assemble in the paracortical T cell zone and present antigen to T lymphocytes. Since splice variants of CD44 promote metastasis of certain tumors to lymph nodes, we explored the expression of CD44 proteins on migrating LC and DC. We show that upon antigen contact, LC and DC upregulate pan CD44 epitopes and epitopes encoded by variant exons v4, v5, v6, and v9. Antibodies against CD44 epitopes inhibit the emigration of LC from the epidermis, prevent binding of activated LC and DC to the T cell zones of lymph nodes, and severely inhibit their capacity to induce a delayed type hypersensitivity reaction to a skin hapten in vivo. Our results demonstrate that CD44 splice variant expression is obligatory for the migration and function of LC and DC.     

Diarrhoea in Kwashiorkor

Diarrhoea was a common problem in the kwashiorkor seen in Kampala, contributing to the mortality and delay in recovery. Enteric infection was found in only a few children (8%), but when present it caused particularly severe diarrhoea and was frequently complicated by septicaemia.Sugar intolerance often occurred to lactose and other sugars, both monosaccharide and disaccharide. The children were most commonly intolerant of lactose, and some of these may have had a hereditary lactase deficiency.Antibiotics are rarely indicated for the treatment of diarrhoea in kwashiorkor in Kampala. If reducing substances are found in the stool of a child on a milk diet, a diet based on sucrose is substituted, and if intolerance persists a fructose diet is given. A few children are intolerant of all sugars, including fructose, and for these the prognosis is grave.     

Characterization and chromosomal distribution of a tandemly repeated DNA sequence from the Australian sheep blowfly,Lucilia cuprina

In the course of making a Lucilia cuprina genomic DNA library, a ladder of bands was seen in partial Sau3A digests. Complete digestion reduced this ladder to predominantly monomer units of approximately 190 bp. Nine independently isolated copies of this repeat were cloned and sequenced. Only two of these isolates are identical in sequence, the most divergent being 71% homologous. This satellite DNA occurs in all three wildtype strains tested, and, for the single case examined, in the embryonic, larval, pupal, and adult DNA. It represents approximately 3%–4% of the genome. Data obtained from in situ chromosome hybridizations indicate that this sequence is concentrated around the centromeric regions of the autosomes and over most of the sex chromosomes. Labelling is much stronger in mitotic compared with polytene chromosomes showing directly that this centromeric satellite DNA is grossly under-replicated during polytenization. This under-replication is even more pronounced on the sex chromosomes compared with the autosomes.by A. Bird The EMBL accession numbers are: X57584 L.C.SAT TRS 188-1; X57585 L.C.SAT TRS 188-13; X57586 L.C.SAT TRS 188-14; X57587 L.C.SAT TRS 188-15; X57588 L.C.SAT TRS 188-19; X57589 L.C.SAT TRS 188-16; X57590 L.C.SAT TRS 188-21; X57591 L.C.SAT TRS 188-7     

Glucocorticoid regulation of enkephalins in cultured rat adrenal medulla

The effect of dexamethasone on enkephalin-containing (EC) peptide levels and preproenkephalin mRNA levels was determined in adrenal medullary explants (glands) from sham and hypophysectomized (hypox) rats. Culture for 4 days in serum-free medium without dexamethasone resulted in a 13- and 4-fold increase in EC peptide levels in sham and hypox glands, respectively. The addition of dexamethasone (10(-5) M) produced a 20- to 26-fold increase in EC peptides in sham and hypox glands. In serum free medium, hypox glands showed a concentration dependent increase in EC peptides with the ED50 for dexamethasone equal to 5.7 x 10(-7) M. Since the glucocorticoid antagonist RU486 partially blocked the rise in EC peptides in sham glands, it appears that the increase in EC peptides in sham glands in the absence of dexamethasone is a result of a higher concentration of endogenous corticosterone in sham compared to hypox glands. Dexamethasone resulted in a 6-fold increase in preproenkephalin mRNA in hypox glands cultured for 2 days. This increase was approximately proportional to the increase in EC peptides seen at 4 days. In serum free medium progesterone, testosterone, and deoxycorticosterone failed to increase EC peptides in hypox glands. These results indicate that glucocorticoid treatment is required for maximal proenkephalin gene expression and EC peptide biosynthesis in cultured glands.     

Effects of dose and time after administration of 4-isopropyl-2,6,7-trioxa-1-phosphabicyclo (2,2,2)octane-1-oxide (IPTBO) on cyclic nucleotide concentrations in mouse cerebellum

The concentrations of cyclic AMP and cyclic GMP in the mouse cerebellum after intracerebroventricular administration of a range of doses of IPTBO have been studied with particular interest in the temporal changes after injection. A non typical dose relationship was observed. After the lowest and non-convulsive dose used (0.06 μg/animal) cyclic AMP levels decreased and cyclic GMP levels increased within 1 min, but after higher doses cyclic AMP and cyclic GMP levels were both raised. At three different convulsive doses of IPTBO there were increased levels of cyclic AMP with time which were more apparent in convulsing animals. Raised levels of cyclic GMP however, were not so influenced by convulsions. The results suggest that (1) the immediate decrease in cyclic AMP and the immediate increase in cyclic GMP may play a part in the mechanism of action of IPTBO—possibly by triggering convulsions and (2) there is an increase in cyclic AMP in response to, or because of, the convulsions. It is concluded that time after treatment and time into convulsions are critical when studying cyclic nucleotide changes, particularly for cyclic AMP and that such factors may explain conflicting observations with respect to this nucleotide.     

Urethral syndrome: a self limiting illness.

Thirty nine adult women who were not pregnant and had the urethral syndrome in a general practice underwent detailed microbiological investigations. Patients monitored their own symptoms, and those with persisting symptoms were entered into a randomised controlled trial of treatment with doxycycline and placebo. Chlamydia trachomatis and Neisseria gonorrhoeae were not isolated and fastidious organisms were not causally associated with the urethral syndrome. Treatment with doxycycline showed no benefit; each episode of the urethral syndrome was short and self limiting and there were no recurrences in a median observation period of 12 months.