Basal cell carcinoma development is associated with induction of the expression of the transcription factor Gli-1

Recent work has established that activation of Hedgehog/patched signalling plays a key role in the development of basal cell carcinomas (BCCs). In Drosophila the effects of hedgehog signalling are mediated by the transcription factor Cubitus interruptus, which is homologous to the mammalian Gli family of transcription factors. In order to investigate the downstream consequences of patched gene inactivation in BCCs, we have investigated the expression of Gli-1 and Gli-3 in normal skin and BCCs by reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization. Gli-3 was found to be expressed in both normal skin and BCCs by both RT-PCR and in situ hybridization using a Gli-3-specific probe. Using a sensitive RT-PCR assay we were unable to detect Gli-1 transcripts in normal skin. Gli-1 was expressed in 13 of 14 BCCs examined, and in situ hybridization confirmed that the transcripts were localized to the epithelial component of the tumours. Our results demonstrate that inactivation of the patched gene BCCs is associated with the accumulation of Gli-1 transcripts. These findings suggest that the Gli-1 transcription factor plays a key role in BCC development.

Zoledronate prevents the development of absolute osteopenia following ovariectomy in adult rhesus monkeys

This study assessed effects of the bisphosphonate zoledronate (ZLN) on bone density and biochemical markers of bone turnover in ovariectomized (OVX) adult female rhesus monkeys. Forty monkeys were randomly assigned to one control or four OVX groups. The control and one OVX group received saline, and the other three OVX groups received ZLN (0.5, 2.5, or 12.5 microg/kg) by a single weekly subcutaneous injection for 69 weeks. Bone mass of the total body (TB), lumbar spine (LS), distal and central radius (dual-energy X-ray absorptiometry), and skeletal turnover markers were measured at baseline and at 13, 26, 39, 52, and 69 weeks of treatment. Increased skeletal turnover and decreased bone mass (LS and TB) were demonstrable by 13 weeks post-OVX. Maximal bone loss (7-8%) at these sites occurred by 39 weeks after OVX and persisted for the study duration. Long-term ZLN treatment was well tolerated and prevented increased skeletal turnover and bone loss in a dose-dependent fashion. Progressive turnover suppression was not observed with any ZLN dose. In conclusion, after OVX, adult rhesus monkeys develop persistent increased bone turnover and absolute osteopenia of the LS and TB, making them an outstanding model of skeletal behavior in perimenopausal women. These OVX-related skeletal changes are dose-dependently blocked by ZLN.

Translation, adaptation, and validation of the SF-36 Health Survey for use in Japan

Development of the Japanese SF-36 was completed in two phases: Phase 1: Japanese version 1.1 was produced according to International Quality of Life Assessment (IQOLA) project guidelines, but some results of psychometric tests were unexpected. First, scores varied little across physical-functioning items. Second, using factor analysis, we could not clearly distinguish the scales designed to measure the "physical" component of quality of life from those designed to measure the "mental" component. Phase 2: Focus-group discussions revealed that limited had often been interpreted as limited by a doctor. Therefore, is difficult to do was used instead (version 1.2). Results of two surveys indicated that version 1.2 yields scores that are reliable by internal consistency and test-retest standards and yields two principal components. In Japan, however, the pattern of correlations between some scales and the principal components differs from that in the United States. Iterative use of qualitative and quantitative methods was very important in developing the Japanese SF-36.

Theory and Experiment on the Measurement of Kinetic Rate Constants for Surfactant Exchange at an Air/Water Interface

The paper focuses on the measurement of the rate constants for the kinetic steps of adsorption and desorption of surfactant between an air/water surface and the aqueous bulk sublayer adjacent to the surface. Kinetic constants are determined in nonequilibrium experiments in which either a clean surface is contacted with a bulk solution and surfactant diffuses toward and adsorbs onto the interface, or the area of an established monolayer in equilibrium with an underlying solution is changed, and surfactant exchanges between the surface and bulk. The dynamic tension change due to the surfactant exchange is measured, and compared to predictions of kinetic-diffusive transport models in order to infer the kinetic coefficients as well the diffusion coefficients. Model comparisons for highly surface active surfactants have resolved only the diffusion coefficient as the transport was found to be diffusion controlled; kinetic constants have only been established for less active materials such as alcohols or bolaform surfactants. In this study, we demonstrate that kinetics can be differentiated from diffusion in clean interface adsorption and re-equilibration if high bulk concentrations of the surfactant are used, or in re-equilibration, if the surface is compressed sufficiently. We first establish theoretically that mass transfer shifts from diffusion-limited to mixed as the bulk concentration increases in clean interface adsorption, or the surface compression is increased in re-equilibration. We then experimentally verify this idea by using the polyethoxylated surfactant C12E6 (C12H25 (OCH2CH2)6-OH) and by measuring dynamic surface tensions in clean interface adsorption and re-equilibration, respectively by the shape analysis of pendant bubbles. We find values of 6 x 10(-10) m2/s for the diffusion coefficient, and 1.4 x 10(-5) m/sec and 1.4 x 10(-4) s-1 for the adsorption and desorption rate constants, respectively, in a Frumkin kinetic formulation. While the adsorption constant is comparable to previously measured values for the less surface active surfactants, the desorption rate constant is a few orders of magnitude smaller. This indicates that the more surface active materials may have much smaller desorption rate constants than had been previously anticipated based on the studies of the less surface active materials. Copyright 1998 Academic Press.

Altering the anaerobic transcription factor FNR confers a hemolytic phenotype on Escherichia coli K12

The recent outbreaks of Escherichia coli O157-associated food poisoning have focused attention on the virulence determinants of E. coli. Here, it is reported that single base substitutions in the fnr gene encoding the oxygen-responsive transcription regulator FNR (fumarate and nitrate reduction regulator) are sufficient to confer a hemolytic phenotype on E. coli K12, the widely used laboratory strain. The mechanism involves enhancing the expression of a normally dormant hemolysin gene (hlyE) located in the E. coli chromosome. The mutations direct single amino acid substitutions in the activating regions (AR1 and AR3) of FNR that contact RNA polymerase. It is concluded that altering a resident transcription regulator, or acquisition of a competent heterologous regulator, could generate a pool of hemolytic, and therefore more virulent, strains of E. coli in nature.

Torsion and kinking of unsupported aortic endografts: treatment by endovascular intervention

PURPOSE

To describe the management strategies used to deal with twisted aortic endografts.

METHODS AND RESULTS

Two patients with successfully excluded aortic aneurysms developed symptoms referable to previously undetected twists in their endografts (one EndoVascular Technologies [EVT] and one customized aortomonoiliac device). The limb graft occlusion in the EVT graft was treated surgically with a femorofemoral bypass, but the aortomonoiliac endograft was salvaged with percutaneous implantation of a Wallstent. During another aortomonoiliac procedure, suboptimal flow through the endograft was traced to contortion of the endograft as it passed over an angulated proximal aneurysm neck. An X-large Palmaz stent was deployed to support the graft at this point.

CONCLUSIONS

Unsupported aortic endografts may develop twists and kinks during deployment that can lead to low outflow and graft occlusion. Endovascular techniques are available to repair these defects postoperatively, although more precise intraoperative assessment tools may identify these problems so that they can be corrected at the initial intervention.

Downregulation of Escherichia coli yfiD expression by FNR occupying a site at -93.5 involves the AR1-containing face of FNR

The promoter of the FNR-activated yfiD gene of Escherichia coli has an unusual architecture because it contains two FNR sites, an arrangement usually associated with FNR-mediated repression. Investigation of yfiD promoter derivatives with altered FNR sites revealed that occupation of the far upstream FNR site (FNR II) downregulated expression, despite the presence of a FNR dimer activating expression from the promoter proximal site (FNR I). Transcript mapping by primer extension, and mutagenesis of potential -10 elements, indicated that yfiD expression is driven from a single FNR-dependent promoter with FNR sites at -40.5 (FNR I) and -93.5 (FNR II). However, yfiD mRNA is processed in stationary-phase cultures independently of rne, rpoS, ihfA and fis to yield transcripts lacking 12 and 21 bases from their respective 5' ends. Single amino acid substitutions (G74-->C, F92-->S, A95-->P, R184-->P, P188-->A or L193-->P) in the surface of FNR that contains activating region 1 (AR1 contacts the alpha-subunit of RNA polymerase to promote transcription activation) reduced the inhibitory effect of FNR at FNR II, indicating that this region of the protein may have a role in repression as well as activation. The FNR variant F92-->S was notable because, although it activated transcription of yfiD (two FNR sites), it was unable to activate transcription from model Class I and II promoters, which contain only a single FNR site.

The effect of cell-matrix interaction on parathyroid hormone (PTH) receptor binding and PTH responsiveness in proximal renal tubular cells and osteoblast-like cells

The interaction of cells with the surrounding extracellular matrix (ECM) or basement membrane (BM) brings about profound changes in cellular biological responses, such as cell differentiation, proliferation, and gene expression. We studied the effect of ECM on PTH receptor binding and on biological responses mediated by PTH, in two cell preparations: 1) the proximal tubular OK opossum kidney cell line; and 2) MC3T3-E1 cells, a clonal line of nontransformed murine osteoblasts. Cells were plated on either plastic surfaces or on tissue culture dishes coated with specific ECM components. In both cell types plated on collagen-type IV (Col-IV), PTH receptor binding, on day 4 of culture, was markedly diminished, when compared with cells on plastic (approximately 45% inhibition, P < 0.01). In addition, Col-IV dose dependently inhibited cAMP generation stimulated by PTH (P < 0.001 vs. plastic), whereas cAMP generation by PGE2, cholera toxin, and forskolin was not altered. In Northern blot analysis, a PTH/PTH-related-protein receptor messenger RNA transcript was detected in both the kidney and bone cells. However, only OK cells manifested a decreased abundance of receptor messenger RNA when plated on Col-IV, compared with plastic. The physiological significance of inhibited cAMP production by Col-IV was evaluated by measuring the influence of different matrices on the activity of Na+/H+ exchanger (NHE) in OK cells and cell mitogenic activity in MC3T3-E1 cells (both responses are negatively modulated by cAMP). OK cells plated on Col-IV showed 70% inhibition of NHE, compared with cells plated on plastic (P < 0.01). PTH inhibits NHE activity in cells on plastic but stimulates exchanger activity by 40% in cells plated on Col-IV. In MC3T3-E1 cells grown on plastic, PTH exerts a dose-dependent antiproliferative effect, which is mediated by cAMP. This effect is mitigated when cells are grown on Col-IV (40-50% less antiproliferative effect). In summary, Col-IV, a maj or BM constituent, has a profound inhibitory effect on PTH binding and PTH-mediated biological responses in both kidney tubular cells and osteoblasts. Altered cellular function by Col-IV may be of physiological relevance in states associated with altered composition of BM or expansion of ECM (e.g. diabetes mellitus and interstitial fibrosis).

Client satisfaction with the New Zealand National Poisons Information Service

A telephone survey of a random sample of callers to the New Zealand National Poisons and Hazardous Chemicals Information Centre (NPC) was undertaken to assess public satisfaction with, and knowledge of, the NPC and to determine whether the NPC was meeting the needs of its users. The response from a sample of 433 individuals (354 members of the general public and 79 health professionals) was 79%. Maori and Pacific Island people were under--represented in the sample. Overall the level of satisfaction with the NPC was high with 91% of the respondents finding the information they received very useful. If the NPC had not been available, 81% of the public would have sought advice from a medical facility and 59% would have visited such a facility. It was estimated that the NPC could be saving the public health services in New Zealand (NZ) up to NZ $1.3 million annually. It was concluded that the NPC was meeting the needs of current users, although greater public awareness and improved access are needed particularly for Maori and Pacific Island people.

Inflammatory cytokines (IL-1alpha, TNF-alpha) and LPS modulate the Ca2+ signaling pathway in osteoblasts

Locally derived growth factors and cytokines in bone play a crucial role in the regulation of bone remodeling, i.e., bone formation and bone resorption processes. We studied the effect of interleukin (IL)-1alpha, tumor necrosis factor (TNF)-alpha, and Escherichia coli lipopolysaccharide (LPS) on the hormone-activated Ca2+ message system in the osteoblastic cell line UMR-106 and in osteoblastic cultures derived from neonatal rat calvariae. In both cell preparations, IL-1alpha, TNF-alpha, and LPS did not alter basal intracellular Ca2+ concentration ([Ca2+]i) but attenuated Ca2+ transients evoked by parathyroid hormone (PTH) and PGE2 in a dose (1-100 ng/ml)- and time (8-24 h)-dependent fashion. The cytokines modulated hormonally induced Ca2+ influx (estimated by using Mn2+ as a surrogate for Ca2+) as well as Ca2+ mobilization from intracellular stores. The latter was linked to suppressed production of hormonally induced inositol 1,4,5-trisphosphate. The effect of cytokines on [Ca2+]i was abolished by the tyrosine kinase inhibitor herbimycin A (50 ng/ml). The cytokine's effect was, however, independent of nitric oxide (NO) production, since NO donors (sodium nitroprusside) as well as permeable cGMP analogs augment, rather than attenuate, hormonally induced Ca2+ transients in osteoblasts. Given the stimulatory role of cytokines on NO production in osteoblasts, the disparate effects of cytokines and NO on the Ca2+ signaling pathway may serve an autocrine/paracrine mechanism for modulating the effect of calciotropic hormones on bone metabolism.

Sexually transmitted disease rates before and after HIV testing

The aim of the study was to evaluate the effect of having an HIV-positive or negative test result on sexual risk behaviour before and after the test. Longitudinal retrospective case-note survey identifying new episodes of sexually transmitted disease (STD) infections in 114 subjects testing HIV positive and 114 matched negatives were examined at the Genitourinary Medicine Department, St Mary's Hospital, Paddington, London. Across the whole sample in the year after HIV testing the number of cases of new STD infections was 40% of the number of cases in the year prior to HIV testing. There was no association between serostatus and incidence of STD infections before and after HIV testing. Of those testing negative, 5.3% were identified as having a new infection in the year after the HIV test, while amongst those testing positive there was a rate of new STDs of 2.6%. In conclusion, there was no evidence that having a negative test result increased the risk of acquisition of new STDs. Rates of new STD infections amongst seropositives in the year after HIV testing were low.

The role of environmental contamination with small round structured viruses in a hospital outbreak investigated by reverse-transcriptase polymerase chain reaction assay

In May 1994 an outbreak of vomiting and diarrhoea occurred in a 28-bed long-stay ward for the mentally infirm. The predominant symptoms were vomiting, diarrhoea, malaise and abdominal pain lasting for approximately 12 h in most cases. The attack rate was 62% (13/21) for patients and 46% (16/35) for staff members. Infection control measures were implemented (containment of infectious individuals, hand hygiene among staff and environmental decontamination) and the ward was closed to admissions. Affected staff were excluded from contact with patients and their food until asymptomatic for 72 h. The outbreak lasted for 17 days. Faecal samples from nine symptomatic persons were negative for bacterial enteric pathogens, Giardia, Cryptosporidium and group A rotavirus. Electron microscopy of 12 faecal samples and one sample of vomitus revealed small round structured virus (SRSV) particles in one faecal sample. A further 30 faecal samples and seven vomitus samples were tested by reverse transcription polymerase chain reaction (RT-PCR) for SRSV of which 12 (40%) and 1 (14%) were positive respectively. Twenty-eight throat swabs from symptomatic and asymptomatic patients were collected, three (9.5%) of which were positive for SRSV by RT-PCR. Thirty-six environmental swabs were collected on the affected ward, and 11 (30%) were positive by RT-PCR. Positive swabs were from lockers, curtains and commodes and confined to the immediate environment of symptomatic patients. The distribution of contamination supports the rationale of cohorting sick patients.

Expression of multiple genes for pregnancy-associated glycoproteins in the sheep placenta

Together these experiments have showed that there are many PAG genes in the ovine genome and many of these are expressed in the placenta. These PAG genes vary as much as 40% in nucleotide sequence identity. Thus, a wide range of ovPAG molecules are secreted at the placental-uterine surface during pregnancy.

An aspartic proteinase expressed in the equine placenta

This manuscript describes the cloning of a novel aspartic proteinase expressed in the placenta of the horse (order Perrisodactyla). Evidence for similar genes in the cat (Carnivora) and ruminants (Artiodactyla), indicates that these molecules have been conserved within widely divergent species with distinct types of placentation. Since ePAG is produced by the outer cell layer (trophoblast) of the placenta, it can tentatively be grouped with the pregnancy-associated glycoproteins (PAG) of cattle, sheep, and pig. The high sequence identity that ePAG shares with pepsinogens as well as the PAG, indicates that ePAG may be the evolutionary bridge that links these two groups of aspartic proteinases.

Estrogen Receptor-α Is Developmentally Regulated during Osteoblast Differentiation and Contributes to Selective Responsiveness of Gene Expression

Estrogen responsiveness of bone is a fundamental regulatory mechanism operative in skeletal homeostasis. We examined the expression of estrogen receptor-alpha (ER) messenger RNA (mRNA) in cultured rat calvarial-derived osteoblasts during progressive development of the osteoblast phenotype. Levels of ER message were compared with the expression of traditional osteoblastic markers that have been mapped throughout the differentiation process of these cells. ER transcripts, measured using semiquantitative RT-PCR analysis, were expressed at low levels in early stage proliferating osteoblasts and increased at confluence upon initial expression of bone cell phenotypic genes. A 23-fold up-regulation of ER mRNA expression coincided with the initiation of alkaline phosphatase activity (day 8). ER mRNA levels progressively increased 70-fold, reaching a maximum level on days 22-25 in fully differentiated osteoblasts when osteocalcin expression peaked, but declined precipitously by day 32 in osteocytic cells. Analysis of RNA isolated directly from rat calvaria confirmed these in vitro results and demonstrated that ER message levels become more abundant postnatally as bone becomes more mineralized. We also examined the responsiveness of osteoblasts to 17beta-estradiol (17beta-E2) at two periods of maturation: the nodule-forming stage (day 14) and the late mineralization stage (day 30). Estradiol suppressed the levels of alkaline phosphatase, osteocalcin, osteonectin, and ER mRNAs on day 14, but up-regulated these messages on day 30. In contrast, 17beta-E2 treatment regulated the steady state levels of transforming growth factor-beta1 and type I procollagen mRNAs only in the late mineralization stage, whereas histone H4 message was unaffected by the steroid at either stage of differentiation. Thus, the observed developmental expression of ER mRNA correlates with progressive osteoblast differentiation and may be a contributing factor to differential regulation of bone cell gene expression by 17beta-E2.

Shortcomings in psychosocial history taking in a paediatric emergency department

OBJECTIVE

To assess the quality of documentation of the psychosocial history taken from parents who repeatedly bring their infants and young children to an emergency department.

METHODOLOGY

We prepared a list of 26 psychosocial items, indicated by the literature to be important elements of a history taken in this setting. We then reviewed subjects' casenotes, and compared each history to this ideal list.

PARTICIPANTS/SETTING

Case note review of 104 children under 2 years who had presented to a paediatric emergency department at least five times in 1 year.

RESULTS

Documentation of psychosocial history for these subjects was very poor, with a mean of only 5 of the 26 possible psychosocial items mentioned per set of casenotes. The majority of records lacked important information, including basic demographic data.

CONCLUSIONS

We canvass possible reasons for poor psychosocial history taking, and argue for changes in medical education, the development of techniques to efficiently identify at risk children and families, and improved resources for referral.

Children's views of accident risks and prevention: a qualitative study

OBJECTIVES

To examine children's accounts of injury risks and opportunities for prevention.

SETTING

Schools, youth clubs, and a holiday activity scheme in the south east of England.

METHODS

Sixteen focus groups were held with 7-11 year old children. Transcripts of the discussions were analysed using qualitative methods.

RESULTS

Children were knowledgeable about injury risks and how to reduce them. They also saw injury prevention as primarily their own responsibility. However, they were also sophisticated in their criticisms of generalised prevention advice, and evaluated safety messages in the light of local environmental and social knowledge. Personal experience was more often reported as a reason for risk reduction than formal prevention advice. Risks for injury were not isolated from other risks faced.

CONCLUSIONS

Effective educational interventions aimed at changing children's risk behaviour should build more on children's own competence and knowledge of their local environment, and stress the need to manage risks rather than avoid dangers.

Cortisol infusion depresses the ratio of bioactive to immunoreactive ACTH in adrenalectomized sheep fetuses

We examined the effects of exogenous cortisol on plasma immunoreactive adrenocorticotropic hormone (iACTH), bioactive ACTH (bACTH), and ACTH-(1-39) in nine adrenalectomized fetuses at 126-130 and 136-140 days of gestation. Fetuses received 4 h of cortisol (2 micrograms.kg-1.min-1) or saline infusions on consecutive days. Blood was obtained before and at intervals during infusions. Arterial blood gases and hematocrits were normal and did not change with age. Plasma cortisol did not change during saline infusions but increased significantly (range 30-70 ng/ml) during cortisol infusions. Basal plasma iACTH, bACTH, ACTH-(1-39), and bACTH-to-iACTH and ACTH-(1-39)-to-iACTH ratios were significantly higher in the older fetuses. Cortisol infusions decreased plasma iACTH, bACTH, and ACTH-(1-39) in both groups, and the suppression as a percent of the baseline was similar. The bACTH-to-iACTH ratio declined to the same level at 126-130 (0.201 +/- 0.040 to 0.051 +/- 0.002) and 136-140 (0.389 +/- 0.088 to 0.046 +/- 0.002) days of gestation. These data suggest that physiological concentrations of cortisol selectively inhibit bACTH secretion, and the ACTH response to cortisol inhibition is not different between 126 and 140 days of gestation in adrenalectomized sheep fetuses.