Does Trans-radial Longitudinal Compression Influence Myoelectric Control?

BACKGROUND

Existing trans-radial prosthetic socket designs are not optimised to facilitate reliable myoelectric control. Many socket designs pre-date the introduction of myoelectric devices. However, socket designs featuring improved biomechanical stability, notably longitudinal compression sockets, have emerged in more recent years. Neither the subsequent effects, if any, of stabilising the limb on myoelectric control nor in which arrangement to apply the compression have been reported.

METHODOLOGY

Twelve able-bodied participants completed two tasks whilst wearing a longitudinal compression socket simulator in three different configurations: 1) compressed, where the compression strut was placed on top of the muscle of interest, 2) relief, where the compression struts were placed either side of the muscle being recorded and 3) uncompressed, with no external compression. The tasks were 1) a single-channel myoelectric target tracking exercise, followed by 2), a high-intensity grasping task. The wearers' accuracy during the tracking task, the pressure at opposing sides of the simulator during contractions and the rate at which the limb fatigued were observed.

FINDINGS

No significant difference between the tracking-task accuracy scores or rate of fatigue was observed for the different compression configurations. Pressure recordings from the compressed configuration showed that pressure was maintained at opposing sides of the simulator during muscle contractions.

CONCLUSION

Longitudinal compression does not inhibit single-channel EMG control, nor improve fatigue performance. Longitudinal compression sockets have the potential to improve the reliability of multi-channel EMG control due to the maintenance of pressure during muscle contractions.

The Effect of Light on Tissue Repair

Electrotherapeutic modalities are widely used by physiotherapists to accelerate repair and reduce pain. It is important that the underlying mechanisms and effects that they produce are fully understood, together with any underlying adverse effects which may arise from their use. Light therapy is a relatively new addition to the physiotherapy arsenal and the mechanisms of action have not yet been fully identified. There is clinical evidence suggesting that it is effective in promoting tissue repair and pain relief. This, together with some recent laboratory evidence showing light to be effective in stimulating cells that are involved in the repair process to produce wound mediators, is described. The weight of evidence suggests that, if used correctly, light therapy can induce bioeffects which are beneficial to the patient.

Targeting EGFR and PI3K pathways in ovarian cancer

Background:

The epidermal growth factor receptor (EGFR) is expressed in ovarian cancer, but agents targeting this pathway have shown little effect as single agents. This may be due to the presence of alternative pathways, particularly activation of the PI3K/Akt/MTOR pathway.

Methods:

We have therefore examined the effect of inhibitors of this pathway (ZSTK474 and sirolimus) in combination with the EGFR inhibitors erlotinib and gefitinib in ovarian cancer primary cell cultures.

Results:

The single-agent EGFR inhibitors showed little activity, although some activity was seen with the single-agent PI3K inhibitor, ZSTK474. Combinations of ZSTK474 with EGFR inhibitors showed enhanced activity with some evidence of synergy, whereas sirolimus combinations were less active. The results were not explicable on the basis of PIK3CA mutation or amplification, or PTEN loss, although one tumour with a KRAS mutation showed resistance to EGFR inhibitors. However, there was correlation of the EGFR expression with sensitivity to EGFR and resistance to PI3K active agents, and inverse correlation in the sensitivity of individual tumours to agents active against these pathways, suggesting a mechanism of action for the combination.

Conclusion:

Phase I/II clinical trials with these agents should include further pharmacodynamic endpoints and molecular characterisation to identify patients most likely to benefit from this strategy.

218.FGF9 stimulates ovarian progesterone production

FGF9, a member of the fibroblast growth factor family (FGF), is known to be a male sex-determining factor involved in testicular cord formation (1). FGF9 knockout males are sex-reversed (2). However, nothing is known about FGF9's role in folliculogenesis because these mice die at birth (2). We previously reported the presence of FGF9 mRNA and protein in the immature rat ovary (3). In these studies we investigated: (1) the presence of FGF9 receptors (FGFR3) on granulosa cells (GC); and (2) the impact of FGF9 on GC progesterone production. GC isolated from 21 day old diethylstilboestrol (DES)-treated rats were cultured for either 2 hours (RNA) or 2 days (progesterone) in McCoys 5C with FGF9 (0.1-50ng/ml) � FSH (100ng/ml). Progesterone was measured in conditioned media by radioimmunoassay. RNA was extracted from the granulosa cells and reverse-transcribed for PCR. Specific primers for P450 side chain cleavage (SCC) amplified a 329�bp cDNA fragment. GAPDH was used for data normalisation. The FGF9 receptor FGFR3, was immunolocalised on formalin-fixed, paraffin-embedded sections of immature rat ovary. FGFR3 protein was localised only to GC of the ovary. Progesterone production by cultured GC was significantly elevated by FGF9, consistent with the presence of FGFR3. Relative to a maximally stimulating dose of FSH, FGF9 increased progesterone production 10- fold. In preliminary studies, FGF9 increased the expression of P450 SCC mRNA by cultured GC revealing a mechanism by which FGF9 increases progesterone production. These data suggest a role for FGF9 not just in testicular formation, but in the regulation of ovarian steroidogenesis. Supported by the NH&MRC of Australia (Regkey 241000 & 198705). (1) Cotinot et al. (2002) Semin. Reprod. Med. 20, 157. (2) Colvin et al. (2001) Cell 104, 875. (3) Drummond et al. (2003) SRB Abstract 90.

Wound healing assessment using 20 MHz ultrasound and photography

BACKGROUND/AIMS

To compare two non-invasive techniques of assessing wound healing, photography and high resolution ultrasound (HRUS) scanning, in experimentally induced full-thickness human skin wounds.

METHODS

Punch biopsy wounds, 4 mm in diameter, were made aseptically through locally anaesthetised skin on the anterior (volar) surface of the non-dominant forearm, 3 cm below the base of the cubital fossa, of 20 human participants. The wounds were treated with a topical antibiotic and covered for 3 days with Mepore sterile dressings. Wound healing was assessed on post-operative days 3, 7, 14 and 21 from photographs and HRUS B-scans. All photographs were taken of the wound site and adjacent intact skin under standardised conditions. The prints obtained were examined visually and digitised. Digital HRUS B-scans were taken through the centre of the wound bed and the adjacent intact skin parallel to the epidermis. Using the scanner's calibrated linear measurement capability, the wound width was measured adjacent to the deep surface of the scab, at the base of the wound, and midway between these two levels.

RESULTS

The wound margins were more clearly defined in the HRUS scans than in the photographs of the wounds; in some of the latter the scab masked the wound margins. Changes in the surface width of the wound were affected by the time of scab dehiscence, which varied between volunteers. There was less individual variation in the width of the base of the wound, as measured from the HRUS scans.

CONCLUSIONS

In contrast to photography, which allows recording of changes in the superficial aspect of the wound only, HRUS scanning permits the quantitative assessment of structural changes deep within the wound. Temporal changes in the width of the base of the wound can be used as an indication of the progress of repair.

The ovarian phenotype of the aromatase knockout (ArKO) mouse

Targeted disruption of exon 9 of the cyp19 gene gives rise to a non-functional aromatase enzyme incapable of converting androgens to oestrogens. The aromatase knockout (ArKO) mouse is, thus, characterised by a dysfunctional pituitary-gonadal axis, which manifests in non-detectable levels of oestrogen in serum. These mice also exhibit elevated levels of circulating gonadotrophins (luteinising hormone (LH) and follicle stimulating hormone (FSH)) and testosterone. The ArKO mouse is infertile due to folliculogenic disruption and a failure to ovulate. The age-dependent ovarian phenotype revealed a block in follicular development at the antral stage and a complete absence of corpora lutea. By 21-23 weeks of age haemorrhagic cystic follicles were present and by 1 year there were abnormal follicles, an absence of secondary and antral follicles and atretic primary follicles. Interstitial tissue remodelling was extensive and exemplified by an increase in collagen deposition and an influx of macrophages, coincident with the loss of follicles. In mice, maintained on a soy-free and, thus, phytoestrogen-free diet, the ovarian phenotype was accelerated and exacerbated. In conclusion, the ovarian phenotype of the ArKO mouse can be attributed to the altered hormonal environment brought about by the absence of aromatase and the failure of androgens to be converted to oestrogens in the presence of elevated gonadotropins.

Growth hormone improves clinical status in prepubertal children with cystic fibrosis: results of a randomized controlled trial

OBJECTIVES

We conducted a 1-year randomized controlled trial to test the hypothesis that growth hormone (GH) improves the clinical status of children with cystic fibrosis.

STUDY DESIGN

Nineteen prepubertal children were randomized to control (NonTX, n = 9) or to daily injections of GH (0.3 mg/kg/wk) (GHTX, n = 10) for 1 year. Every 3 months height, weight, and lean tissue mass were measured. Caloric intake, resting energy expenditure, pulmonary function, and respiratory muscle strength were measured every 6 months, as were total number of hospitalizations and courses of outpatient intravenous antibiotics.

RESULTS

The GHTX group had significantly greater height, height velocity (NonTX = 3.8 +/- 1.4 cm/y, GHTX = 8.1 +/- 2.4 cm/y; P =.002), weight, weight velocity (NonTX = 2.1 +/- 0.9 kg/y, GHTX = 4.5 +/- 1.1 kg/y; P =.004), and change in lean tissue mass (NonTX = 2.1 +/- 1.6 kg, GHTX = 4.7 +/- 1.7 kg; P =.01) analyzed by the Student t test. The GHTX group had significant improvement in delta forced vital capacity compared with the year before study, and respiratory muscle strength improved. The number of hospitalizations and outpatient intravenous antibiotic courses significantly decreased in the GHTX group but did not change in the NonTX group. No subject had development of cystic fibrosis-related diabetes.

CONCLUSIONS

Results of the first randomized controlled trial of GH treatment in cystic fibrosis indicate that GH improves growth and clinical status.

Growth hormone decreases protein catabolism in children with cystic fibrosis

Despite aggressive nutritional therapy, low body weight and protein catabolism are common problems in children with cystic fibrosis. Previous studies by our group and others have demonstrated improvement in both height and weight in children with cystic fibrosis who were treated with human recombinant GH, and our group has recently documented improved clinical status and lean tissue mass as well. The purpose of this report is to summarize our findings of the effect of GH on whole body protein kinetics in cystic fibrosis and to relate these findings to changes in TNF-alpha levels. We conducted a 1-yr study of 19 prepubertal children with cystic fibrosis (age 7-12 yr, all <94% of ideal body weight). Ten children were randomly assigned to take daily injections of GH (0.3 mg/kg.wk), and nine were randomly assigned to be controls. Baseline results from the subjects with cystic fibrosis were compared with results obtained from nine age- and gender-matched healthy children. Whole body protein turnover was measured at baseline and every 6 months using the stable isotope [1-(13)C]leucine and mass spectrometric analysis. Leucine rate of appearance, a measure of protein catabolism, was similar in both cystic fibrosis subgroups at baseline and was significantly higher than in the control children without cystic fibrosis. Treatment with GH resulted in a significantly lower leucine rate of appearance, as well as significantly lower leucine oxidation. The rate of protein synthesis, as calculated from these numbers, actually decreased in the cystic fibrosis subgroup. TNF-alpha levels were higher in both cystic fibrosis subgroups than in controls and correlated with leucine rate of appearance. The results of this study suggest that one reason GH improves body weight and lean tissue mass is due to improved whole body protein catabolism and improved efficiency of whole body protein kinetics.

Production and actions of inhibin and activin during folliculogenesis in the rat

Evidence to enhance the premise that inhibin and activin are local regulators of ovarian folliculogenesis is presented in this review. Granulosa cells (GC) have been identified as the source of inhibin/activin in the ovary on the basis of mRNA and protein localisation and the measurement of the inhibin forms in GC conditioned media. Expression of the subunit mRNAs changed with follicular development, being maximal in the ovaries of 8-day-old rats, where secondary follicles predominate. The expression of beta subunit mRNAs by GC isolated from diethylstilboestrol (DES)-treated immature rats, was reduced in the absence of any change in alpha subunit mRNA expression. Dimeric inhibin-A, -B and free alpha subunit were produced by ovarian cell cultures prepared from 4- to 12-day-old rats. Inhibin-A production by these cultures was responsive to FSH and TGF-beta, with preantral follicles of day 8 ovaries exerting effects so profound that the inhibin A/alpha subunit ratio increased, most likely due to a stimulation of beta(A) subunit production. In contrast, inhibin-B was not stimulated by TGF-beta until day 8 and FSH until day 12. Fractionation of GC conditioned media revealed a prominence of free alpha subunit and inhibin-A, but little inhibin-B, suggesting that inhibin-B production declines with follicular development. Activin receptor types I and II, Smads 1-8 and betaglycan (beta-glycan) mRNAs were present in the rat ovary and showed distinct patterns of expression between postnatal days 4 and 12. Oocytes and GC localised activin receptor, Smad and beta-glycan proteins, with beta-glycan also present in theca cells (TC). These data indicate that activin/TGF-beta signalling machinery and factors which influence these pathways, are present in the postnatal rat ovary. Our hypothesis that inhibin and activin play important and changing autocrine/paracrine roles in the growth and differentiation of follicles, including the oocyte, has been supported by these studies.

Elements involved in the regulation of the StAR gene

The steroidogenic acute regulatory protein (StAR) mediates the transfer of cholesterol from the outer to the inner mitochondrial membrane, the regulated step in steroidogenesis. A most interesting facet of this protein is the manner in which its expression is acutely regulated. In this regard, a number of studies have concentrated on the search for consensus cis regulatory elements within its promoter, and, more importantly, on whether these elements are involved in its expression. This short review will summarize some of the findings that have been reported concerning the nature of how the expression of this gene is regulated.

The use of high-frequency diagnostic ultrasound to investigate the effect of hormone replacement therapy on skin thickness

BACKGROUND/AIMS

Previous investigations have suggested that hormone replacement therapy (HRT) could have a positive effect on the maintenance of skin thickness post-menopause. Previous skin measurement devices have proved variable in their accuracy and ease of use. This investigation assessed the effect of HRT on the skin in a noninvasive way, using high-frequency diagnostic ultrasound.

METHOD

The study was a cross-sectional observational study, carried out at a menopause and gynaecology outpatient's clinic. A total of 84 women (comprising 34 HRT users, 25 post-menopausal controls, and 25 premenopausal controls) took part in the study. Each volunteer was scanned using diagnostic ultrasound on the arm. Skin thickness measurements were made from each scan using computerised image analysis.

RESULTS

Skin thickness was shown to be greater in the HRT group than in the post-menopausal controls (P<0.01).

CONCLUSIONS

High-frequency diagnostic ultrasound proved to be a useful clinical tool and showed that HRT appears to help maintain skin thickness in menopause.

High-frequency ultrasound imaging of the skin during normal and hypertensive pregnancies

BACKGROUND/AIMS

Diagnosis of preeclampsia is currently made from blood pressure measurements taken at antenatal visits (either at the hospital or in the community). The aim of this work was to see whether the presence of underlying hypertensive diseases is accompanied by changes in the skin of pregnant women, which can be visualized using high-frequency diagnostic ultrasound.

METHODS

This was a prospective study of pregnant and non-pregnant, hypertensive and non-hypertensive patients visiting the outpatient department of a central London Teaching Hospital. The study group consisted of 93 women, of which 30 were non-hypertensive in the second trimester of pregnancy, 26 were non-hypertensive in the third trimester of pregnancy, 9 were hypertensive in the second trimester of pregnancy, and 14 were hypertensive in the third trimester of pregnancy. Fourteen non-pregnant women of comparable age were recruited as controls. Changes in abdominal skin thickness and also skin structure, as analysed by fractal image analysis, was assessed in each patient.

RESULTS

In a normal pregnancy, abdominal skin gets thinner as pregnancy progresses. In hypertensive patients, the skin thickness did not appear to alter. Image analysis of abdominal skin scans showed that the skin of non-hypertensive pregnant women and non-pregnant women are different. Whereas the analysis of hypertensive pregnant women and non-pregnant women showed they were the same.

CONCLUSIONS

The data used to compare the groups indicates that if the abdominal skin of the patient does not get thinner as the pregnancy progresses there is an indication that the patient may be hypertensive. The fractal data comparing the groups indicates the following when comparing a patient's fractal signature with the non-pregnant control data: If the abdominal fractal for a pregnant woman is similar to the control group, there is an indication that the patient is hypertensive. It is difficult to predict hypertension in patients, and it is possible that a patient could develop severe preeclampsia between visits to the antenatal clinics. Therefore, if the high-frequency ultrasound scanner can pick up potential hypertensives early in pregnancy, these women could be identified as potentially high risk.

Reproductive stage and history affect the phonotactic preferences of female midwife toads, Alytes muletensis

We investigated whether the reproductive stage or reproductive history of females affects their preferences for male calls that differ in frequency. We repeatedly tested gravid female midwife toads prior to and immediately after mating, and during ovulation. When females were ovulating they were much more consistent in their choice of call than when they were gravid but not ovulating. When females had recently mated they still showed positive phonotaxis, but did not reliably discriminate between alternative calls. This study is the first to test gravid female anurans repeatedly at different stages in their reproductive cycle (ovulating or not; pre- and postmating). It highlights the need to treat with caution the results from population-based preference studies in which individuals are tested only once, and in which variation in reproductive state is not taken into account. Copyright 2000 The Association for the Study of Animal Behaviour.

Temporal and hormonal regulation of inhibin protein and subunit mRNA expression by post-natal and immature rat ovaries

The contribution of specific follicle populations to dimeric inhibin production and inhibin subunit mRNA expression by the rat ovary has been investigated in two model systems, granulosa cells isolated from 25-day-old diethylstilboestrol (DES)-treated rats and post-natal rat ovaries, dispersed in culture or whole ovaries, using specific two-site immunoassays and 'real time' PCR. Media from FSH-stimulated granulosa cell cultures fractionated by gel filtration and RP-high performance liquid chromatography revealed two predominant peaks of alpha subunit activity which were attributed to alpha subunit and 31 k dimeric inhibin-A. The corresponding inhibin-B levels were low. FSH stimulation did not alter the ratio of inhibin-A:alpha subunit produced by granulosa cells. All three inhibin subunit mRNAs were expressed by granulosa cells, with eight-fold more alpha subunit mRNA relative to either of the beta subunits. Administration of DES to immature rats prior to the isolation of granulosa cells from the ovary led to beta(A) and beta(B) mRNA expression being down-regulated in the absence of any significant change in alpha subunit expression by the granulosa cells. Inhibin-A, -B and -alpha subunit were produced by basal and stimulated cultures of ovarian cells prepared from 4-, 8- and 12-day-old rats, indicating that primary, preantral and antral follicles contribute to total inhibin production. Consistent with these results, follicles within these ovaries expressed all three inhibin subunit mRNAs, with maximal expression observed in the ovaries of 8-day-old rats. The appearance of antral follicles in the ovary at day 12 led to a decline in the mRNA levels of each of the subunits but was most evident for the beta subunits. There was a profound influence of secondary preantral follicles on dimeric inhibin-A production, with FSH stimulation increasing inhibin-A relative to alpha subunit levels in cultures of ovarian cells prepared from 8-day-old rats. Thus, preantral follicles exposed to FSH contribute significantly to beta(A) subunit production by the ovary. In contrast, primary and preantral follicles did not produce inhibin-B in response to FSH stimulation. Transforming growth factor-beta (TGF-beta) enhanced, in a time-dependent manner, the production of the inhibin forms by ovarian cells in culture, although inhibin-B production was not responsive until day 8. The simultaneous treatment of ovarian cell cultures with FSH and TGF-beta elicited the greatest increases in production of all the inhibin forms. In summary, ovaries of 4-, 8- and 12-day-old rats expressed inhibin subunit mRNAs and produced dimeric inhibin-A and -B and free alpha subunit. Preantral follicles (day-8 ovarian cell cultures) were particularly sensitive to stimulation by FSH and TGF-beta and had a substantial capacity for inhibin production. The production of oestrogen by follicles may be instrumental in regulating inhibin production given that beta subunit mRNA expression was down-regulated by DES. The mechanisms by which inhibin-A and inhibin-B are individually regulated are likely to be similar during the post-natal period, when folliculogenesis is being established, and diverge thereafter, when inhibin-A becomes the predominant form in the fully differentiated ovary.

An age-related ovarian phenotype in mice with targeted disruption of the Cyp 19 (aromatase) gene

With the development of a mouse model of estrogen insufficiency due to targeted disruption of the aromatase gene [the aromatase knockout (ArKO) mouse], a new opportunity exists to examine the role of estrogen in ovarian follicular development. Ovaries and serum were collected from wild-type, heterozygous, and ArKO mice at 10-12 and 21-23 weeks and 1 yr of age. The ovaries were assessed histologically and stereologically, with primary, secondary, and antral follicles and corpora lutea counted. The uteri were hypoestrogenic, and serum levels of LH and FSH in ArKO females were elevated above those in heterozygote and wild-type animals at all ages studied. Although estrogen was not a prerequisite for reinitiation of follicle growth, there was a block of follicular development, and no corpora lutea were present in ArKO ovaries. Thus, the ArKO mouse was infertile as a consequence of disrupted folliculogenesis and a failure to ovulate. Hemorrhagic cystic follicles were present by 21-23 weeks of age. The ovarian phenotype degenerated with age, such that by 1 yr there were no secondary or antral follicles, and the primary follicles present were atretic. Extensive interstitial tissue remodeling occurred, exemplified by an influx of macrophages and collagen deposition, coincident with the loss of follicles. In conclusion, the ovarian environment in ArKO mice does not allow the characteristic development of follicles that culminates in ovulation and demonstrates an in vivo requirement of estrogen for normal ovarian function in the mouse.

Stimulatory effect of 660 nm low level laser energy on hypertrophic scar-derived fibroblasts: possible mechanisms for increase in cell counts

BACKGROUND AND OBJECTIVE

Varying effects of red light wavelengths on in vitro cells have been reported. Low level lasers (LLL) are employed to assist wound healing especially for indolent ulcers. On healing, burn wounds may become hypertrophic, resulting in excessive wound contraction, poor cosmesis, and functional impairment. This study enquired whether 660 nm LLL affected hypertrophic scar-derived fibroblasts.

STUDY DESIGN/MATERIALS AND METHODS

The experiments investigated the effect of a 660 nm, 17 mW laser diode at dosages of 2.4 J/cm2 and 4 J/cm2 on cell counts of two human fibroblast cell lines, derived from hypertrophic scar tissue (HSF) and normal dermal (NDF) tissue explants, respectively. The protocol avoided transfer of postirradiated cells. Estimation of fibroblasts utilized the methylene blue bioassay.

RESULTS/CONCLUSION

The post-660 nm-irradiated HSFs exhibited very significantly higher cell counts than controls P < 0.01 on days 1-4 (Mann-Whitney U-test), and P < 0.01 on days 1-3 for similarly irradiated NDFs.

Laser modulation of angiogenic factor production by T-lymphocytes

BACKGROUND AND OBJECTIVE

In previous investigations, small variations in the energy densities of low level light therapy (LLLT) were found to produce significant differences in the proliferation of resting T-lymphocytes in vitro. Pulsing these cells with mitogen in addition to laser therapy produced inhibitory effects regardless of the amplitude of the energy density used. In the current study, the effect of LLLT on the production of angiogenic factor(s) by T-lymphocytes was investigated in vitro.

STUDY DESIGN/MATERIALS AND METHODS

Human T-cells isolated from peripheral blood were prepared in suspension either with or without addition of mitogen. Cell suspensions were irradiated with laser by using the following energy densities: 1.2, 3.6, 6.0, and 8.4 J/cm(2). Wavelength, pulsing frequency, and power output were kept constant at 820 nm, 5,000 Hz, and 50 mW, respectively. After either 3 or 5 days of incubation, lymphocyte supernatants were collected and added as conditioned media to cultured endothelial cells (ECs). The effect on the proliferation of these ECs was assessed over a 72-hour period by using a methylene blue assay.

RESULTS

Endothelial cell proliferation increased significantly when incubated with conditioned media collected from resting T-cells exposed to 1.2 and 3.6 J/cm(2). Day 5 conditioned media produced similar patterns of EC proliferation to that of day 3 but at lower magnitude. Pulsing of T-lymphocytes with mitogen in addition to laser irradiation significantly lessened their angiogenic capability. Conditioned media from 3.6 J/cm(2) laser-treated T-cells induced the maximal EC proliferation in all groups studied.

CONCLUSION

It would seem that laser therapy stimulates lymphocytes to produce factor(s) that can modulate EC proliferation in vitro; this effect on the lymphocytes is influenced by (1) the amplitude of energy density used for T-cell irradiation, (2) exposing T-cells to both mitogen and laser, and (3) the duration of T-cell incubation in culture.

The roles of activins, inhibins and estrogen in early committed follicles

The hypothesis that activin and inhibin are autocrine/paracrine mediators of ovarian folliculogenesis has a solid basis. In mouse and rat models, granulosa cells (GC) of committed follicles express mRNA and protein for the activin/inhibin subunits and mRNA for the activin receptors (type I and II). Dimeric inhibin-A and -B are produced by postnatal ovarian cell dispersates and (GC) in culture. Similar levels of inhibin-A and -B are produced by postnatal ovarian cells, but thereafter as the ovary develops, inhibin-A becomes the predominant form. Activin was more effective than transforming growth factor-beta (TGF-beta) in enhancing follicle stimulating hormone (FSH)-stimulated inhibin production by ovarian cells. Evidence for a local regulatory role of estrogen in the ovary is also accumulating. Murine models of estrogen receptor (ERalpha or ERbeta) disruption produce mice with abnormal ovarian phenotypes. Female mice, which lack the capacity to produce estrogen (ArKO mice), have arrested folliculogenesis, no corpora lutea, elevated levels of luteinising hormone (LH), FSH and testosterone and are infertile. These data are consistent with autocrine/paracrine actions of activin in the early growth of committed follicles and estrogen in follicular maturation.

A therapy-relevant casemix classification system for school-age children with disabilities

OBJECTIVE

To develop a clinically meaningful classification system of resource-homogeneous groups to describe therapy resource use for school-age children with disabilities.

DESIGN

Work-time allocation survey of therapy services (physical therapists, occupational therapists, and speech pathologists).

SETTING

Three main disability agencies in Western Australia. CLIENTS: All children of two agencies, a random sample of children of the third. A total of 644 clients and their services were studied.

MAIN OUTCOME MEASUREMENT

Minutes of therapy service time expected over a 10-week school term.

RESULTS

Forty-six percent of the variance in a measure of time spent with clients can be explained using a classification system of nine groups, based on splitting a mobility measure (4 major groups), then the nature of primary disorder (2 subgroups), independence in self care (3 subgroups), and expressive communication (3 subgroups).

CONCLUSION

This study defines a preliminary classification system for the distribution of therapy resources to school-age children with disabilities. This model has the potential to be used to purchase services on a fairer basis than traditional, historical funding methods have allowed.

Immuno-inflammatory cell dynamics during cutaneous wound healing

The process of wound healing begins with an inflammatory reaction that is principally dependent on cellular immune elements. Although the involvement in wound healing of leucocytes that mediate nonspecific immunity (e.g. neutrophils and macrophages) is well known, the participation of cells which prime the immune reaction, i.e. the lymphocytes, requires further investigation. This study was performed to examine the temporal sequence and kinetics of these cells during cutaneous wound repair. The model selected was a full-thickness skin excisional wound made on the flanks of female Wistar rats. At time points ranging from 3 h to 2 wk wound samples were processed for polyester wax-embedding. Target antigens were identified and monitored quantitatively in sections stained immunohistochemically. Monoclonal antibodies against neutrophils, macrophages, pan T cells and cytotoxic populations of lymphocytes were used. The results showed that these cells are involved in the process of wound healing in a distinctive dynamic pattern. The accumulation of CD3+ T lymphocytes in the wound bed was mainly associated with the phase of granulation tissue formation. Intraepithelial CD3+ T lymphocytes were detected in considerable numbers within the regenerating epidermis. The cytotoxic cell populations (OX8+) were classified morphologically into the cytotoxic/suppressor subset of T cells and NK cells. The OX8+ T cells were shown to have a kinetic pattern similar to CD3+ T lymphocytes but of a lower magnitude. The accumulation of OX8+ NK cells was confined to the early inflammatory phase of repair. It is concluded that CD3+ T lymphocytes as well as OX8+ cytotoxic populations of the immune system are involved in the process of cutaneous wound healing in temporal sequences which suggest that they may be involved in its modulation.

Intensive care unit psychosis, the therapeutic nurse-patient relationship and the influence of the intensive care setting: analyses of interrelating factors

It has been estimated that between 12.5% and 38% of conscious patients admitted to critical care settings experience Intensive Care Unit psychosis, a condition which seems to resolve upon transfer to the ward. This phenomenon was traditionally recognized when the patient outwardly exhibited abnormal behaviours and signs in the form of confusion, delirium, anxiety, depression, delusions and audiovisual hallucinations, yet it has been argued that due to the illness of the patient and their suppressed ability to communicate, such overt displays of unusual behaviour are the tip of the iceberg. In recognizing this phenomenon, it is felt that a relationship exists between Intensive Care Unit Psychosis, the therapeutic nurse-patient relationship, and the environment in which nurses' interactions with their clients occur. This paper will explore the interaction between these three elements while considering the implications for contemporary nursing practice.

The effects of ovarian hormone deficiency on wound contraction in a rat model

OBJECTIVE

To demonstrate the effect of a deficiency of ovarian hormones on the process of wound contraction, using the oophorectomised rat model of the human menopause.

DESIGN

A randomised controlled trial.

POPULATION

Ninety-six adult Wistar rats were randomly allocated into either an oophorectomised group or a sham-oophorectomised control group.

METHODS

Having confirmed a significant reduction in plasma oestradiol levels in the oophorectomised rats, full-thickness excised lesions were made in the flank skin of the adult rats at either two weeks or four months after oophorectomy, so that the effects of two different durations of hormone deficiency could be assessed and compared with the sham-oophorectomised controls. Following wounding, the rats were left for 3, 5, 10 or 22 days; wound contraction was assessed from photographs of the wounds taken at these intervals after injury.

RESULTS

In the rats wounded four months after oophorectomy there was a slower rate of wound contraction, resulting in larger wounds at days 3, 5, 10 and 22, compared with control rats. No significant difference was observed in rats wounded two weeks after oophorectomy, indicating that the effects of ovarian hormone deficiency on this process are delayed.

CONCLUSION

Due to the pivotal role of wound contraction in the process of wound healing these findings may be of clinical relevance and could have an important impact on the administration of hormone replacement therapy.

Regulation of follistatin production by rat granulosa cells in vitro

The aims of this study were to apply enzyme-linked immunosorbent assays (ELISA) for human follistatins (FS) to measure total immunoreactive (ir-) rat FS and free rat FS, and investigate the regulation of production of total ir-FS and free FS by rat granulosa cells (GC) in vitro. Production of ir-inhibin was monitored as an index of GC function. The ELISAs for total ir-FS, based on an immunoradiometric assay developed recently for human FS, and free FS, based on capture of FS by a monoclonal antibody and detection by activin A binding, had sensitivities of 0.4 and 0.8 ng recombinant human (rh-) FS 288/ml, respectively, and did not cross-react with inhibin A, rLH, or FSH. rh-Activin did not cross react in the total ir-FS ELISA, but interfered with the measurement of free FS. Dilutions of GC-conditioned medium were parallel to the standard curve of rh-FS 288 for each assay. The values obtained in the free FS assay were 10- to 20-fold higher than those in the total ir-FS ELISA, suggesting that rat FS may be recognized by the antibodies differently than the human standard. Both total ir-FS and free FS production by undifferentiated GC from diethylstilbestrol (DES)-treated, immature rats increased with cell number and time in culture and were stimulated dose dependently by FSH, rh-activin A (except free FS, which was not measured because of interference), forskolin, and phorbol 12-myristrate. The effects of FSH and activin on FS production by undifferentiated GC were additive. There were significant effects of degree of differentiation of GC on basal FS production and responsiveness to FSH, LH, and rh-activin A. Both total ir-FS and free basal FS production increased up to 4-fold with the degree of differentiation of GC, produced by treating rats in vivo with DES (undifferentiated), DES plus FSH (partially differentiated), or DES plus FSH plus hCG (fully differentiated). The addition of FSH in vitro increased FS production by undifferentiated and partially differentiated GC, but not by fully differentiated GC. The only detectable effect of LH on FS production was on partially differentiated GC. Activin A stimulated total ir-FS production by undifferentiated and partially differentiated GC, but inhibited total ir-FS production by fully differentiated GC. Ir-inhibin production in these experiments was similar to that of FS with the following exceptions; phorbol 12-myristrate inhibited ir-inhibin production by undifferentiated GC, basal ir-inhibin decreased in fully differentiated GC, FSH stimulated ir-inhibin only in undifferentiated GC, and rh-activin A stimulated ir-inhibin at all stages. It is concluded that 1) FS protein production by cultured undifferentiated rat GC is up-regulated by FSH and activin, possibly via both protein kinase A and C pathways; 2) increasing GC differentiation is associated with a significant increase in basal FS production by rat GC and a change in the hormonal regulation of FS production; and 3) FS and ir-inhibin production by cultured rat GC can be differentially regulated. The results are consistent with the hypothesis that activin tone decreases within follicles as they develop due to increased production of the activin-binding protein FS.

The ontogeny of adhesion molecules expressed on the vascular endothelium of the developing human skin

One of the important functions of adhesion molecules is to regulate the trafficking of lymphocytes and other leucocytes between the different organs and tissues of the body. These molecules are expressed on both the endothelial cells and the leucocytes, enabling them to adhere to one another and ultimately lead to extravasation of the leucocytes from the circulation into the surrounding tissue. P and E-selectin promote 'rolling' of leucocytes along the blood vessel walls, whereas ICAM-1 and VCAM-1 mediate subsequent firm adhesion, thus committing the leucocytes to extravasation. We have investigated the expression of the above endothelial adhesion molecules in relation to the developing dermal vasculature of fetal skin using histology and immunocytochemistry. This study showed that already at 11 wk of gestation some dermal vessels expressed P-selectin and ICAM-1. However, by 18 wk these molecules were identified on a significant number of vessels, including small capillaries supplying the forming dermal pegs. In contrast, E-selectin and VCAM-1 molecules were rarely seen in all specimens examined. Our results show that even at 11 wk of gestation, the fetal skin has a mechanism in place for circulating leucocytes to extravasate and provide primitive immunosurveillance. Furthermore, the similarities between the distribution of P-selectin and ICAM-1 in the 18 wk fetal skin and in the normal adult skin were striking. These findings may shed light on our understanding of how the fetus detects and reacts to infections and may, in the future, lead to advances in the management of some intrauterine infections.

Differential responses of post-natal rat ovarian cells to FSH and activin

A role for activin in the acquisition of gonadotropin responsiveness by the post-natal rat ovary was investigated. The inhibin/activin subunits in terms of protein and mRNA, were localised in granulosa cells of the rat ovary at days 4, 8 and 12 after birth. A characteristic pattern of responses to FSH for inhibin and progesterone (P) production was established using a dispersed ovarian cell bioassay. P production by day 4, 8 and 12 cultures was stimulated by FSH, but only when iso-butyl-methyl-xanthine (MIX) was present. In contrast, a basal level of inhibin production was measured in day 4 cultures which was not responsive to FSH or MIX. In day 8 and 12 cultures, inhibin production was FSH-responsive, but only in the absence of MIX. The addition of activin to cultures of day 4, 8 and 12 ovarian cells induced FSH-responsive P production and stimulated both basal and FSH-stimulated inhibin production. These studies indicate a differential response of neonatal ovarian cells to FSH in terms of P and inhibin production. Activin may play a role in facilitating the effects of FSH on signal transduction pathways leading to inhibin and steroid production and therefore be part of the mechanism which determines responsiveness of granulosa cells to FSH.

Modern critical care unit design. Nursing implications in modern critical care unit design: bed area ergonomics

Management of the bed area in the critical care unit is important in terms of patient management and occupational safety of healthcare staff. There are many fundamental considerations concerning the design, layout and aesthetics of the bed area. The aesthetics should be an amalgamation of the expectations of patients, relatives and healthcare staff. Most of the activity is centered in the patient care area, and facilities should be designed according to ergonomic considerations.

Oestradiol and immunoreactive inhibin-like secretory patterns following controlled ovarian hyperstimulation with urinary (Metrodin) or recombinant follicle stimulating hormone (Puregon)

Inhibin (and its alpha-subunit) may be of particular value as a marker for follicular development in in-vitro fertilization (IVF) in comparison with the classic follicle stimulating hormone (FSH)-dependent marker oestradiol in patients following pituitary desensitization and treatment with recombinant FSH (rFSH). This preparation lacks luteinizing hormone (LH), which is essential for thecal cell androgen secretion and thus oestradiol production. Our study has assessed oestradiol and immunoreactive inhibin-like secretion following ovarian stimulation with rFSH or a purified urinary FSH preparation (Metrodin) (uFSH). A randomized, assessor-blind study was initiated using patients receiving a single treatment cycle of IVF (using fresh embryos) following pituitary desensitization with intranasal buserelin (500 microg daily) and the i.m. injection of either rFSH (n = 38) or uFSH (n = 17). Ovarian ultrasound examinations were performed and bloods (10 ml) collected prior to FSH treatment and every 1-2 days until ovulation induction with human chorionic gonadotrophin. LH and FSH concentrations were measured by an immunoradiometric assay, and inhibin-like immunoreactivity by a radioimmunoassay and an enzyme-linked immunosorbent assay, both with alpha-subunit specificity. Oestradiol concentration was measured with a coated tube radioimmunoassay. Following desensitization, basal LH, FSH and oestradiol concentrations were measured, as was that of immunoreactive inhibin. Following treatment with either rFSH or uFSH, LH concentrations remained low while FSH concentrations rose to a plateau of 5.6-6.7 IU/l in both groups. In contrast, the concentration of oestradiol was higher (P < 0.05) with rFSH than with uFSH in the last four days of treatment, a pattern that was repeated for inhibin-like immunoreactivity. The change in oestradiol and inhibin concentrations during treatment was approximately 2-fold higher with rFSH. The total number of follicles obtained with rFSH was similar to that with uFSH. However, the number of follicles with a diameter of >/= 15 mm was higher the rFSH group, and there was a concomitant increase in the number of oocytes recovered. Oestradiol concentration and inhibin-like immunoreactivity (determined by either method) were associated with total follicle number and number of follicles >/= 15 mm in diameter, as well as with each other (P < 0.001). When ovarian hormone output was normalized per follicle produced, oestradiol output was higher for rFSH than for uFSH P = 0.04). Inhibin output was clearly higher using rFSH than uFSH. There were seven pregnancies (one miscarriage) with rFSH and two with uFSH. Despite similar concentrations od FSH in patients, rFSH (Puregon) appears to be more potent in vitro in terms of follicular number, ovarian hormone secretion (both concentration and output/follicle) and oocyte recovery. In both groups, LH concentrations of approximately 1.3 IU/l were sufficient to support oestradiol secretion similar to that normally found in IVF programmes using human menopausal gonadotrophin preparations containing large amounts of LH. Despite known problems of specificity with the assays od inhibin, its measurement was of similar value to oestradiol as a marker of follicular development.

Effect of laser pulse repetition rate and pulse duration on mast cell number and degranulation

BACKGROUND AND OBJECTIVE

Mast cell activation by low-level laser therapy (LLLT), leading to degranulation and the release of mediators, may be one of the mechanisms by which LLLT can accelerate tissue repair in mammals. The objective of this work, part of an investigation to determine the optimum parameters for increasing mast cell number and degranulation in injured skin, was to determine the effect of different pulsing frequencies of LLLT.

STUDY DESIGN/MATERIALS AND METHODS

Partial-thickness wounds in anaesthetized adult male Wistar rats were irradiated immediately after injury with monochromatic coherent light (wavelength 820 nm) pulsed at either 2.5, 20, 292, or 20,000 Hz at an average power density of 800 mW/cm2 for 27 seconds; the energy density was 21.6 J/cm2. The effects on mast cell number and degranulation were assessed 2 hours post-treatment by counting the numbers of intact and degranulated mast cells in Carnoy-fixed, toluidine blue-stained, sections of irradiated and sham-irradiated wounds.

RESULTS

The total number of mast cells was increased significantly (P < 0.05) by all the frequencies when compared to the sham-irradiated group, but there was no significant difference between frequencies (P > 0.05). However, although the number of degranulated mast cells was higher in all laser-treated wounds, in comparison with the sham-irradiated group, only the 20 Hz (pulse duration 45 ms) and 292 Hz (pulse duration 3 ms) frequencies were significantly effective (P < 0.05).

CONCLUSION

Increase in mast cell number is not pulsing frequency dependent, whereas degranulation is.

Use of splenic ultrasound: a new wave for immune thrombocytopenic purpura

AIMS

To examine whether a therapeutic dose of ultrasound waves, when directed through the thoracic wall to the spleen, would significantly affect the platelet count in patients with stable immune thrombocytopenic purpura (ITP).

METHODS

Continuous ultrasound at 1 W/cm2 spatial average-time average (SATA) intensity for up to one minute/5 cm2 treatment field was well tolerated in 13 patients with ITP and one with non-Hodgkin's lymphoma. Five healthy controls were also similarly treated. Peak platelet increments occurred four to eight hours after ultrasound treatment in the ITP group (n = 16 treatments).

RESULTS

The mean peak platelet increment was 6.25 x 10(9)/l with a 5% confidence interval of the mean (95% CI) of 3.32 to 8.93 x 10(9)/l (p = 0.0004). The mean peak platelet increment of normal controls was 6.6 (n = 5; 95% CI = -2.3 to 15.5; p = 0.21) and for sham treated patients it was 0.66 (n = 11; 95% CI = -1.5 to 2.8; p = 0.60). There was a significant inverse correlation between patient age in the ITP group and peak platelet increment (r = -0.60; p = 0.015).

CONCLUSIONS

Splenic ultrasound is a novel approach to the treatment of ITP, and may find a place in its diagnosis or management.

Histochemical heterogeneity of mast cells in rat dermis

The dermal mast cells of Wistar rats were studied following fixation in either 10% phosphate buffered formalin or Carnoy's solution and staining with either toluidine blue or alcian blue:safranin O. Granules of mast cells appeared heterogeneous following fixation with formalin and staining with alcian blue:safranin O, but not when stained with toluidine blue. The number of mast cells observed in skin fixed in Carnoy's solution was greater than the number observed in equivalent samples of skin fixed in formalin (p < 0.01) when both samples were stained with toluidine blue. In formalin fixed skin stained with alcian blue:safranin O, there were three populations of mast cells designated as "blue," "red" or "mixed." "Blue" mast cells, containing only alcian blue stained granules, "red" mast cells, containing only safranin O stained granules, and "mixed" mast cells, containing both alcian blue and safranin O stained granules accounted for 77.6 +/- 3.0, 6.6 +/- 2.5 and 15.8 +/- 2.5% of the total mast cell population, respectively. In skin specimens fixed in Carnoy's solution and stained with alcian blue:safranin O the mast cells contained only blue granules (alcian blue positive). The number of mast cells observed in Carnoy's fixed skin sections was less than the number seen in formalin fixed skin sections when both were stained with alcian blue/safranin O. This indicates that there is a group of mast cells which do not stain with safranin O after fixation with Carnoy's solution.

The effects of follistatin, activin and inhibin on steroidogenesis by bovine thecal cells

The paracrine actions of bovine follistatin (FS), human recombinant activin A and bovine inhibin on progesterone (P), androstenedione (A4) and inhibin production, were investigated using LH-stimulated immature bovine thecal cells. The presence of FS (3-100 ng/ml) alone caused a dose-dependent stimulation of P production by thecal cells induced by bovine LH (10 ng/ml). The stimulatory effect of FS on P production at 10 or 30 ng/ml was reversed to control levels with the addition of activin (10 or 30 ng/ml). Treatment with FS did not significantly effect on A4 production. Activin alone had no consistent effect on A4 production (measured using two different antibodies), but had a dose-dependent inhibitory effect on P production. Treatments of cells with inhibin had no significant effect on the LH-induced production of either P or A4. Testosterone production in FS; activin- or inhibin-treated cells was not different from controls. Northern analysis showed that inhibin beta subunit was not detected in thecal mRNA, whereas there were very faint bands of inhibin alpha subunit and FS which were attributed to contamination of granulosa cells (GC). We conclude that FS in vitro has a stimulatory effect on P production by bovine thecal cells, and that activin has the ability to reverse the stimulatory effect of P production. Unlike the rat and human thecal cells, activin and inhibin had no significant effect on LH-induced androgen synthesis by bovine thecal cells. We propose that FS secreted by the GC acts as a paracrine modulator upon thecal cells to directly stimulate the production of P independently of activin.(ABSTRACT TRUNCATED AT 250 WORDS)

Responses of dermal mast cells to injury

The effect on dermal mast cell numbers and degranulation of making a partial thickness skin wound on the right flank of Wistar rats was studied immediately after operation and 0.5, 1, 2, 4, 8, 16, 24 and 72 h postoperatively. An equivalent area of intact dermis on the left flank was used as a control. In the injured dermis the mean number of detectable mast cells in the experimental group immediately after making the partial thickness wound was not significantly different from the control side (P > 0.25) but it later decreased, reaching its lowest value after 2 h and increasing from 16 h to 72 h postoperatively when the final assessment was made. The possibility that the reduction in mast cell number per unit area might be an artefact resulting from increased tissue volume due to oedema was investigated and disproved. The total number of dermal mast cells in equivalent areas of the intact left flank remained unchanged throughout this period. The percentage of degranulating mast cells started rising 0.5 h postoperatively, increased gradually to reach its highest value after 2 h, remained high up to 8 h postoperatively and then decreased to reach its lowest value after 72 h. The percentage of degranulating mast cells of the intact dermis of the left flank did not alter during this period. The lack of a significant change in the control groups shows either the absence of any systemic effect or that the technique used was not sensitive enough to detect it.

Comparison of the effects of moist and dry conditions on the process of angiogenesis during dermal repair

The effect of moist and dry conditions on the process of angiogenesis during dermal repair was investigated. The moist conditions were achieved by covering excised wounds on porcine flank skin with the adhesive polyurethane dressing Opsite and dry conditions were achieved by exposure to air through dry gauze dressings. Angiogenesis was assessed during the period from 3 to 60 d after injury. Quantitative studies, using computerized image analysis, were carried out on microfocal x-ray images of skin sections whose blood system had been perfused in vivo with a radio-opaque medium. The analytical technique yielded information with regard to vessel number per wound and also the area occupied by blood vessels per unit wound area. Three regions were assessed in each wound bed: upper zone, just below the surface of the wound; the lower zone, just above the base of the wound bed; and the middle zone, midway between the other two zones. The results showed that the wounds maintained in a moist environment revascularized at a greater rate than those maintained in a dry environment. This was apparent in all of the zones of the wound bed examined. The development of new vessels occurred in a more orderly manner in the moist wounds. There was an early increase in vessel number rising to a peak around days 3-5, then a gradual decrease in number starting around day 7. In contrast, in the dry wounds the development of blood vessels was less rapid. Peak vessel number in the upper zone was significantly less than that achieved in the moist wounds, and was not reached until 7 d after injury. The decrease in vessel number from the peak was less rapid in the dry wounds, suggesting that there was a delayed entry into the remodeling phase in comparison with the moist wounds. The results also showed that the total percentage area of the wound bed occupied by blood vessels was greater in the moist wounds than the dry wounds from 3 d after injury until day 7. This level of vascularization was maintained beyond 7 d after injury even when the vessel number in the moist wounds was significantly less than in the dry wounds, suggesting that the vessels in the moist wounds were larger and, presumably, more mature. In general, moist wounds showed a more rapid decline towards uninjured skin levels of vascularization than dry wounds.