Book Review "Selling sex: a hidden history of prostitution", R. Frances, UNSW Press, Sydney, 2007

In the opening pages of Selling Sex we are introduced to 'Joy', a statue of a young female sex worker which stood in East Sydney for eighteen months during 1995- 1997. Following complaints by local residents, the statue was removed from public view and returned to its owner. Evidently, Joy was considered a reminder of the community's 'bad old days', when it was better known for prostitution than restaurants. In a nation in which almost every sizable community has proudly erected monuments to military men, the removal of Joy reveals much about labour and gender relations in Australia. For Frances, the removal of Joy is symbolic, our historical treatment of sex workers having parallels with our treatment of the convicts. This work sets out to give these women (male prostitutes do not figure in this history) a voice and break with the stereotypes of 'abandoned whores' or 'sad victims'. It also sets out to place the sex industry in the broader national and international context in which it has historically operated...

Expression of intracellular calcium signalling genes in cattle skin during tick infestation

It is widely acknowledged that changes in intracellular calcium ion (Ca2+) concentration provide dynamic signals that control a plethora of cellular processes, including triggering and mediating host defence mechanisms. In this study, quantitative real-time PCR was used to analyse gene expression of 14 Ca2+ signalling proteins in skin obtained from high tick-resistant (HR) and low tick-resistant (LR) cattle following artificial challenge with cattle tick (Rhipicephalus (Boophilus) microplus). Up-regulation of numerous genes was observed in both HR and LR skin following tick challenge, however substantially higher transcription activation was found in HR tissue. The elevated expression in HR skin of specific Ca2+ signalling genes such as AHNAK, CASQ, IL2, NFAT2CIP and PLCG1 may be related to host resistance. Our data suggest that Ca2+ and its associated proteins might play an important role in host response to ticks and that further investigation is warranted.

Cinnamate toxicity expression on phenylalanine ammonia-lyase activity, germination and growth of cucumber (Cucumis sativis) seedlings

Cinnamate is the product of phenylalanine ammonialyase (PAL). This compound, a precursor of phenolics in plants, has been shown to be phytotoxic. Cinnamate inhibits PAL activity in cucumber seedlings. DL-phenylalanine has the same effect on the enzyme but does not affect growth. Actinomycin D and cycloheximide are phytotoxic and inhibit PAL. Production of a double-peg has been noticed in the seedlings, grown in the presence of actinomycin D. Light stimulates PAL activity in the seedling.

Expression of functional GABAc receptors in the brain

γ-aminobutyric acid (GABA) is the main inhibitory transmitter in the nervous system and acts via three distinct receptor classes: A, B, and C. GABAC receptors are ionotropic receptors comprising ρ subunits. In this work, we aimed to elucidate the expression of ρ subunits in the postnatal brain, the characteristics of ρ2 homo-oligomeric receptors, and the function of GABAC receptors in the hippocampus. In situ hybridization on rat brain slices showed ρ2 mRNA expression from the newborn in the superficial grey layer of the superior colliculus, from the first postnatal week in the hippocampal CA1 region and the pretectal nucleus of the optic tract, and in the adult dorsal lateral geniculate nucleus. Quantitative RT-PCR revealed expression of all three ρ subunits in the hippocampus and superior colliculus from the first postnatal day. In the hippocampus, ρ2 mRNA expression clearly dominated over ρ1 and ρ3. GABAC receptor protein expression was confirmed in the adult hippocampus, superior colliculus, and dorsal lateral geniculate nucleus by immunohistochemistry. From the selective distribution of ρ subunits, GABAC receptors may be hypothesized to be specifically involved in aspects of visual image motion processing in the rat brain. Although previous data had indicated a much higher expression level for ρ2 subunit transcripts than for ρ1 or ρ3 in the brain, previous work done on Xenopus oocytes had suggested that rat ρ2 subunits do not form functional homo-oligomeric GABAC receptors but need ρ1 or ρ3 subunits to form hetero-oligomers. Our results demonstrated, for the first time, that HEK 293 cells transfected with ρ2 cDNA displayed currents in whole-cell patch-clamp recordings. Homomeric rat ρ2 receptors had a decreased sensitivity to, but a high affinity for picrotoxin and a marked sensitivity to the GABAC receptor agonist CACA. Our results suggest that ρ2 subunits may contribute to brain function, also in areas not expressing other ρ subunits. Using extracellular electrophysiological recordings, we aimed to study the effects of the GABAC receptor agonists and antagonists on responses of the hippocampal neurons to electrical stimulation. Activation of GABAC receptors with CACA suppressed postsynaptic excitability and the GABAC receptor antagonist TPMPA inhibited the effects of CACA. Next, we aimed to display the activation of the GABAC receptors by synaptically released GABA using intracellular recordings. GABA-mediated long-lasting depolarizing responses evoked by high-frequency stimulation were prolonged by TPMPA. For weaker stimulation, the effect of TPMPA was enhanced after GABA uptake was inhibited. Our data demonstrate that GABAC receptors can be activated by endogenous synaptic transmitter release following strong stimulation or under conditions of reduced GABA uptake. The lack of GABAC receptor activation by less intensive stimulation under control conditions suggests that these receptors are extrasynaptic and activated via spillover of synaptically released GABA. Taken together with the restricted expression pattern of GABAC receptors in the brain and their distinctive pharmacological and biophysical properties, our findings supporting extrasynaptic localization of these receptors raise interesting possibilities for novel pharmacological therapies in the treatment of, for example, epilepsy and sleep disorders.

Expression of cytochrome P450 enzymes and metabolism of timolol in human ocular tissue

Glaucoma is a group of progressive optic neuropathies causing irreversible blindness if not diagnosed and treated in the early state of progression. Disease is often, but not always, associated with increased intraocular pressure (IOP), which is also the most important risk factor for glaucoma. Ophthlamic timolol preparations have been used for decades to lower increased intraocular pressure (IOP). Timolol is locally well tolerated but may cause e.g. cardiovascular and pulmonary adverse effects due to systemic absorption. It has been reported that approximately 80% of a topically administered eye drop is systemically absorbed. However, only limited information is available on timolol metabolism in the liver or especially in the human eye. The aim of this work was to investigate metabolism of timolol in human liver and human ocular tissues. The expression of drug metabolizing cytochrome P450 (CYP) enzymes in the human ciliary epithelial cells was studied. The metabolism of timolol and the interaction potential of timolol with other commercially available medicines were investigated in vitro using different liver preparations. The absorption of timolol to the aqueous humor from two commercially available products: 0.1% eye gel and 0.5% eye drops and the presence of timolol metabolites in the aqueous humor were investigated in a clinical trial. Timolol was confirmed to be metabolized mainly by CYP2D6 as previously suggested. Potent CYP2D6 inhibitors especially fluoxetine, paroxetine and quinidine inhibited the metabolism of timolol. The inhibition may be of clinical significance in patients using ophthalmic timolol products. CYP1A1 and CYP1B1 mRNAs were expressed in the human ciliary epithelial cells. CYP1B1 was also expressed at protein level and the expression was strongly induced by a known potent CYP1B1 inducer 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The CYP1B1 induction is suggested to be mediated by aryl hydrocarbon receptor (AHR). Low levels of CYP2D6 mRNA splice variants were expressed in the human ciliary epithelial cells and very low levels of timolol metabolites were detected in the human aqueous humor. It seems that negligible amount of CYP2D6 protein is expressed in the human ocular tissues. Timolol 0.1% eye gel leads to aqueous humor concentration high enough to achieve therapeutic effect. Inter-individual variation in concentrations is low and intraocular as well as systemic safety can be increased when using this product with lower timolol concentration instead of timolol 0.5% eye drops.

Expression and function of angiotensins in the regulation of intraocular pressure - an experimental study

Glaucoma is a multifactorial long-term ocular neuropathy associated with progressive loss of the visual field, retinal nerve fiber structural abnormalities and optic disc changes. Like arterial hypertension it is usually a symptomless disease, but if left untreated leads to visual disability and eventual blindness. All therapies currently used aim to lower intraocular pressure (IOP) in order to minimize cell death. Drugs with new mechanisms of action could protect glaucomatous eyes against blindness. Renin-angiotensin system (RAS) is known to regulate systemic blood pressure and compounds acting on it are in wide clinical use in the treatment of hypertension and heart failure but not yet in ophthalmological use. There are only few previous studies concerning intraocular RAS, though evidence is accumulating that drugs antagonizing RAS can also lower IOP, the only treatable risk factor in glaucoma. The main aim of this experimental study was to clarify the expression of the renin-angiotensin system in the eye tissues and to test its potential oculohypotensive effects and mechanisms. In addition, the possible relationship between the development of hypertension and IOP was evaluated in animal models. In conclusion, a novel angiotensin receptor type (Mas), as well as ACE2 enzyme- producing agonists for Mas, were described for the first time in the eye structures participating in the regulation of IOP. In addition, a Mas receptor agonist significantly reduced even normal IOP. The effect was abolished by a specific receptor antagonist. Intraocular, local RAS would thus to be involved in the regulation of IOP, probably even more in pathological conditions such as glaucoma though there was no unambiguous relationship between arterial and ocular hypertension. The findings suggest the potential as antiglaucomatous drugs of agents which increase ACE2 activity and the formation of angiotensin (1-7), or activate Mas receptors.

Androgen receptor-dependent and independent functions of ARIP4

Androgen receptor (AR) is necessary for normal male phenotype development and essential for spermatogenesis. AR is a classical steroid receptor mediating actions of male sex steroids testosterone and 5-alpha-dihydrotestosterone. Numerous coregulators interact with the receptor and regulate AR activity on target genes. This study deals with the characterization of androgen receptor-interacting protein 4 (ARIP4). ARIP4 binds DNA, interacts with AR in vitro and in cultured yeast and mammalian cells, and modulates AR-dependent transactivation. ARIP4 is an active DNA-dependent ATPase, and this enzymatic activity is essential for the ability of ARIP4 to modulate AR function. On the basis of sequence homology in its ATPase domain, ARIP4 belongs to the SNF2 family of proteins involved in chromatin remodeling, DNA repair, and homologous recombination. Similar to its closest homologs ATRX and Rad54, ARIP4 does not seem to be a classical chromatin remodeling protein in that it does not appear to form large protein complexes in vivo or remodel mononucleosomes in vitro. However, ARIP4 is able to generate superhelical torsion on linear DNA fragments. ARIP4 is covalently modified by SUMO-1, and mutation of six potential SUMO attachment sites abolishes the ability of ARIP4 to bind DNA, hydrolyze ATP, and activate AR function. ARIP4 expression starts in early embryonic development. In mouse embryo ARIP4 is present mainly in the neural tube and limb buds. In adult mouse tissues ARIP4 expression is virtually ubiquitous. In mouse testis ARIP4 is expressed in the nuclei of Sertoli cells in a stage-dependent manner. ARIP4 is also present in the nuclei of Leydig cells, spermatogonia, pachytene and diplotene spermatocytes. Testicular expression pattern of ARIP4 does not differ significantly in wild-type, FSHRKO, and LuRKO mice. In the testis of hpg mice, ARIP4 is found mainly in interstitial cells and has very low, if any, expression in Sertoli and germ cells. Heterozygous Arip4+/ mice are fertile and appear normal; however, they are haploinsufficient with regard to androgen action in Sertoli cells. In contrast, Arip4 / embryos are not viable. They have significantly reduced body size at E9.5 and die by E11.5. Compared to wild-type littermates, Arip4 / embryos possess a higher percentage of apoptotic cells at E9.5 and E10.5. Fibroblasts derived from Arip4 / embryos cease growing after 2-3 passages and exhibit a significantly increased apoptosis and decreased proliferation rate than cells from wild-type embryos. Our findings demonstrate that ARIP4 plays an essential role in mouse embryonic development. In addition, testicular expression and AR coregulatory activity of ARIP4 suggest a role of ARIP4-AR interaction in the somatic cells of the testis.

Sexing Sirenians: Validation of Visual and Molecular Sex Determination in Both Wild Dugongs (Dugong dugon) and Florida Manatees (Trichechus manatus latirostris)

Sexing wild marine mammals that show little to no sexual dimorphism is challenging. For sirenians that are difficult to catch or approach closely, molecular sexing from tissue biopsies offers an alternative method to visual discrimination. This paper reports the results of a field study to validate the use of two sexing methods: (1) visual discrimination of sex vs (2) molecular sexing based on a multiplex PCR assay which amplifies the male-specific SRY gene and differentiates ZFX and ZFY gametologues. Skin samples from 628 dugongs (Dugong dugon) and 100 Florida manatees (Trichechus manatus latirostris) were analysed and assigned as male or female based on molecular sex. These individuals were also assigned a sex based on either direct observation of the genitalia and/or the association of the individual with a calf. Individuals of both species showed 93 to 96% congruence between visual and molecular sexing. For the remaining 4 to 7%, the discrepancies could be explained by human error. To mitigate this error rate, we recommend using both of these robust techniques, with routine inclusion of sex primers into microsatellite panels employed for identity, along with trained field observers and stringent sample handling.

Molecular Mechanisms of Androgen Receptor Interactions

The androgen receptor (AR) mediates the effects of the male sex-steroid hormones (androgens), testosterone and 5?-dihydrotestosterone. Androgens are critical in the development and maintenance of male sexual characteristics. AR is a member of the steroid receptor ligand-inducible transcription factor family. The steroid receptor family is a subgroup of the nuclear receptor superfamily that also includes receptors for the active forms of vitamin A, vitamin D3, and thyroid hormones. Like all nuclear receptors, AR has a conserved modular structure consisting of a non-conserved amino-terminal domain (NTD), containing the intrinsic activation function 1, a highly conserved DNA-binding domain, and a conserved ligand-binding domain (LBD) that harbors the activation function 2. Each of these domains plays an important role in receptor function and signaling, either via intra- and inter-receptor interactions, interactions with specific DNA sequences, termed hormone response elements, or via functional interactions with domain-specific proteins, termed coregulators (coactivators and corepressors). Upon binding androgens, AR acquires a new conformational state, translocates to the nucleus, binds to androgen response elements, homodimerizes and recruits sequence-specific coregulatory factors and the basal transcription machinery. This set of events is required to activate gene transcription (expression). Gene transcription is a strictly modulated process that governs cell growth, cell homeostasis, cell function and cell death. Disruptions of AR transcriptional activity caused by receptor mutations and/or altered coregulator interactions are linked to a wide spectrum of androgen insensitivity syndromes, and to the pathogenesis of prostate cancer (CaP). The treatment of CaP usually involves androgen depletion therapy (ADT). ADT achieves significant clinical responses during the early stages of the disease. However, under the selective pressure of androgen withdrawal, androgen-dependent CaP can progress to an androgen-independent CaP. Androgen-independent CaP is invariably a more aggressive and untreatable form of the disease. Advancing our understanding of the molecular mechanisms behind the switch in androgen-dependency would improve our success of treating CaP and other AR related illnesses. This study evaluates how clinically identified AR mutations affect the receptor s transcriptional activity. We reveal that a potential molecular abnormality in androgen insensitivity syndrome and CaP patients is caused by disruptions of the important intra-receptor NTD/LBD interaction. We demonstrate that the same AR LBD mutations can also disrupt the recruitment of the p160 coactivator protein GRIP1. Our investigations reveal that 30% of patients with advanced, untreated local CaP have somatic mutations that may lead to increases in AR activity. We report that somatic mutations that activate AR may lead to early relapse in ADT. Our results demonstrate that the types of ADT a CaP patient receives may cause a clustering of mutations to a particular region of the receptor. Furthermore, the mutations that arise before and during ADT do not always result in a receptor that is more active, indicating that coregulator interactions play a pivotal role in the progression of androgen-independent CaP. To improve CaP therapy, it is necessary to identify critical coregulators of AR. We screened a HeLa cell cDNA library and identified small carboxyl-terminal domain phosphatase 2 (SCP2). SCP2 is a protein phosphatase that directly interacts with the AR NTD and represses AR activity. We demonstrated that reducing the endogenous cellular levels of SCP2 causes more AR to load on to the prostate specific antigen (PSA) gene promoter and enhancer regions. Additionally, under the same conditions, more RNA polymerase II was recruited to the PSA promoter region and overall there was an increase in androgen-dependent transcription of the PSA gene, revealing that SCP2 could play a role in the pathogenesis of CaP.

Sex Determination - A Hypothesis Based On Noncoding Dna

Certain recent models of sex determination in mammals, Drosophila melanogaster, Caenorhabditis elegans, and snakes are examined in the light of the hypothesis that the relevant genetic regulatory mechanisms are similar and interrelated. The proposed key element in each of these instances is a noncoding DNA sequence, which serves as a high-affinity binding site for a repressor-like molecule regulating the activity of a major "sex-determining" gene. On this basis it is argued that, in several eukaryotes, (i) certain DNA sequences that are sex-determining are noncoding, in the sense that they are not the structural genes of a sex-determining protein; (ii) in some species these noncoding sequences are present in one sex and absent in the other, while in others their copy number or accessibility to regulatory molecules is significantly unequal between the two sexes; and (iii) this inequality determines whether the embryo develops into a male or a female.