Marine macroalgal biodiversity hotspots: why is there high species richness and endemism in southern Australian marine benthic flora?

The southern Australian marine macroalgal flora has the highest levels of species richness and endemism of any regional macroalgal flora in the world. Analyses of species composition and distributions for the southern Australian flora have identified four different floristic elements, namely the southern Australian endemic element, the widely distributed temperate element, the tropical element and a cold water element. Within the southern Australian endemic element, four species distribution patterns are apparent, thought to largely result from the Jurassic to Oligocene fragmentation of East Gondwana, the subsequent migration of Tethyan ancestors from the west Australian coast and the later invasion of high latitude Pacific species. Climatic deterioration from the late Eocene to the present is thought responsible for the replacement of the previous tropical south coast flora by an endemic temperate flora which has subsequently diversified in response to fluctuating environmental conditions, abundant rocky substrata and substantial habitat heterogeneity. High levels of endemism are attributed to Australia's long isolation and maintained, as is the high species richness, by the lack of recent mass extinction events. The warm water Leeuwin Current has had profound influence in the region since the Eocene, flowing to disperse macroalgal species onto the south coast as well as ameliorating the local environment. It is now evident that the high species richness and endemism we now observe in the southern Australian marine macroalgal flora can be attributed to a complex interaction of biogeographical, ecological and phylogenetic processes over the last 160 million years.

Study of the effectiveness of propolis extract as a storage medium for avulsed teeth

The purpose of the present study was to evaluate the efficacy of propolis extract in maintaining the viability of human periodontal ligament (PDL) cells, and to radiographically analyze tooth replantation and the adjacent periodontium in dogs after storage in this extract. Human PDL cells were incubated with the experimental media propolis, milk, saliva, Hank`s balanced salt solution (HBSS), and Dulbecco`s modified Eagles medium (DMEM, positive controls), and distilled water (negative control). Cell viability was determined 0, 1, 3, 6, 12, and 24 h later by colorimetric MTT assay. Thirty incisors from dogs were divided into two storage time blocks (1 and 3 h) and were maintained in the experimental media. HBSS served as a positive control, and dry teeth (on gauze) as a negative control. The replanted teeth were radiographed once per month for 6 months. The radiographic images were standardized by the shortening/lengthening factor, and were both qualitatively and quantitatively analyzed. The in vitro results showed that the efficacy of propolis in maintaining functional viability of PDL cells was similar to that of milk. Propolis and milk were significantly better than controls from the 6-h time period. The in vivo results showed that teeth maintained in propolis medium exhibited replacement resorption with significant reduction in tooth length, similar to teeth maintained in saliva and dried teeth. This resorption was less intense with the 3-h storage time than the 1-h storage time. Conditions close to normal were found in teeth maintained in milk, similar to the HBSS control. Therefore, although propolis was effective in maintaining the viability of human PDL cells, resorption of the tooth replantation in dogs occurred under these experimental conditions.

Modulatory role of locus coeruleus and estradiol on the stress response of female rats

The activity of the hypothalamic-pituitary-adrenal axis is modulated by the norepinephrinergic system and, in females, also by the ovarian hormones. We investigated the role of ovarian steroids and the locus coeruleus (LC) on stress-induced corticosterone secretion in female rats. Ovariectomized rats without hormonal replacement (OVX) or treated with estradiol (OVE) or estradiol plus progesterone (OVEP) were subjected to jugular cannulation. Immediately after that, each hormonal treatment group was subjected to LC lesion or sham surgery or no brain surgery. After 24 h, blood samples of all 9 groups were collected before and after ether inhalation. Other four groups (OVX control, sham and lesioned, and OVE) were perfused for glucocorticoid receptor (GR) immunocytochemistry in hippocampal CA1 neurons and paraventricular nucleus (PVN). Estradiol replacement decreased while LC lesions increased stress-induced corticosterone secretion. The effect of LC lesion was potentiated with the removal of ovarian steroids. Since GR expression of lesioned animals decreased in the hippocampus, but not in PVN, we suggest that the effect of LC lesion on corticosterone secretion could be due to a reduction in the efficiency of the negative feedback system in the CA1 neurons. However, this mechanism is not involved in the estradiol modulation on corticosteroid secretion, as no change in GR expression was observed in estradiol-treated animals.

Evaluation of estrogen neuroprotective effect on nigrostriatal dopaminergic neurons following 6-hydroxydopamine injection into the substantia nigra pars compacta or the medial forebrain bundle

Studies involving estrogen treatment of ovariectomized rats or mice have attributed to this hormone a neuroprotective effect on the substantia nigra pars compacta (SNpc) neurons. We investigated the effect of estradiol replacement in ovariectomized rats on the survival of dopaminergic mesencephalic cell and the integrity of their projections to the striatum after microinjections of 1 mu g of 6-hydroxydopamine (6-OHDA) into the right SNpc or medial forebrain bundle (MFB). Estradiol replacement did not prevent the reduction either in the striatal concentrations of DA and metabolites or in the number of nigrostriatal dopaminergic neurons following lesion with 1 mu g of 6-OHDA into the SNpc. Nevertheless, estradiol treatment reduced the decrease in striatal DA following injection of 1 mu g of 6-OHDA into the MFB. Results suggest therefore that estrogen protect nigrostriatal dopaminergic neurons against a 6-OHDA injury to the MFB but not the SNpc. This may be due to the distinct degree of lesions promoted in these different rat models of Parkinson`s disease.

Effect of growth hormone on in vitro osteogenesis and gene expression of human osteoblastic cells is donor-age-dependent

it has been demonstrated that the effect of GH on bone tissue is reduced with aging. In this study we tested the hypothesis that the action of GH on osteoblastic cells is donor-age-dependent by investigating the effect of GH on the development of osteoblastic phenotype in cultures of cells from adolescents (13-16 years old), young adults (18-35 years old), and adults (36-49 years old). Osteoblastic cells derived from human alveolar bone were cultured with or without GH for periods of up to 21 days, and parameters of in vitro osteogenesis and gene expression of osteoblastic markers were evaluated. GH increased culture growth, collagen content and alkaline phosphatase (ALP) activity in cultures from adolescents and young adults, whereas non-significant effect was observed in cultures from adults. While GH significantly increased the bone-like formation in cultures from adolescents, a slightly effect was observed in cultures from young adults and no alteration was detected in cultures from adults. Results from real-time PCR demonstrated that GH upregulated ALP, osteocalcin, type I collagen, and Cbfa1 mRNA levels in cultures from adolescents. In addition, cultures from young adults showed higher ALP mRNA expression and the expression of all evaluated genes was not affected by GH in cultures from adults. These results indicate that the GH effect on both in vitro osteogenesis and gene expression of osteoblastic markers is donor-age-dependent, being more pronounced on cultures from adolescents.

The expression of plasminogen activator system in a rat model of periodontal wound healing

Background: The plasminogen activator system has been proposed to play a role in proteolytic degradation of extracellular matrices in tissue remodeling, including wound healing. The aim of this study was to elucidate the presence of components of the plasminogen activator system during different stages of periodontal wound healing. Methods: Periodontal wounds were created around the molars of adult rats and healing was followed for 28 days. Immunohistochemical analyses of the healing tissues and an analysis of the periodontal wound healing fluid by ELISA were carried out for the detection of tissue-type plasminogen activator (t-PA), urokinase-type plasminogen activator (u-PA), and 2 plasminogen activator inhibitors (PAI-1 and PAI-2). Results: During the early stages (days 1 to 3) of periodontal wound healing, PAI-1 and PAI-2 were found to be closely associated with the deposition of a fibrin clot in the gingival sulcus. These components were strongly associated with the infiltrating inflammatory cells around the fibrin clot. During days 3 to 7, u-PA, PAI-1, and PAI-2 were associated with cells (particularly monocytes/macrophages, fibroblasts, and endothelial cells) in the newly formed granulation tissue. During days 7 to 14, a new attachment apparatus was formed during which PAI-1, PAI-2, and u-PA were localized in both periodontal ligament fibroblasts (PDL) and epithelial cells at sites where these cells were attaching to the root surface. In the periodontal wound healing fluid, the concentration for t-PA increased and peaked during the first week. PAI-2 had a similar expression to t-PA, but at a lower level over the entire wound-healing period. Conclusions: These findings indicate that the plasminogen activator system is involved in the entire process of periodontal wound healing, in particular with the formation of fibrin matrix on the root surface and its replacement by granulation tissue, as well as the subsequent formation of the attachment of soft tissue to the root surface during the later stages of wound repair.

Polymorphisms of the renin-angiotensin system in patients with multifocal renal arterial fibromuscular dysplasia

Fibromuscular dysplasia (FMD) is an important cause of renal artery stenosis, particularly in young females. Polymorphisms of the renin-angiotensin (RA) system have been implicated in the pathogenesis of hypertension and atherosclerotic vascular disease, and may play a role in the development of FMD. Examination of polymorphisms by PCR for angiotensin-converting enzyme (ACE) I/D, angiotensin II type 1 receptor (AT(1)R) A1166C and angiotensinogen (AGT) M235T and T174M was undertaken in 43 patients with typical multifocal renal arterial FMD (MF-FMD) and in 89 controls. The age of NIF-FMD patients at the time of diagnosis of hypertension did not differ (38.6 + 11.1 years vs 35.5 +/- 10.3 years, P = 0.12) from controls and the proportion (95% vs 86%, P = 0.14) of females was similar. Allele frequencies did not differ significantly between groups, except that MF-FMD patients had a significantly higher frequency of the ACE I allele than control subjects (0.62 vs 0.47, P = 0.026). Since the ACE I allele is associated with lower circulating ACE levels and possibly lower tissue levels of angiotensin II (Ang II), and since Ang II modulates vascular smooth muscle cell growth and synthetic activity, the I allele might predispose to defective remodelling of the arterial media, and thus to the development of MF-FMD. This contrasts with atherosclerotic renal artery stenosis, coronary stent restenosis and carotid intimal thickening, which are diseases affecting the arterial intima, and which are associated with increased frequency of the D allele.

A servicing strategy for items sold under warranty

When repairable items sold under warranty fail, the rectification action taken by the manufacturer can be either a repair or a replacement, In this paper a new repair-replacement strategy is proposed for the manufacturer when the items are sold with a non-renewing free replacement warranty policy. The strategy involves splitting the warranty period into two intervals where only repairs are carried out, separated by a third interval with at most one replacement.

Living with osteoarthritis: Patient expenditures, health status, and social impact

Objective. To determine out-of-pocket expenditures related to osteoarthritis (OA) and to explore whether demographic details, health status scores (Medical Outcomes Study 36-item Short Form [SF-36] and Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), or perception of social effect were expenditure determinants. Methods. A prospective cohort study of community-dwelling subjects with OA completed 4 consecutive 3-month cost diaries. In addition, subjects completed the SF-36 and WOMAC at baseline and at 12 months. Social impact at baseline was collected. Four groups categorized by age and sex were compared. Patients undergoing joint replacement were excluded. Results. Differences in health status were defined more by age than by sex, especially for physical function. The costs to the patients were high, particularly for women, who spent more on medications and special equipment. Women also reported receiving more assistance from family and friends. Higher disease-related expenditures were associated with greater pain levels, poorer social function and mental health, and longer duration of disease. Significant independent predictors of total patient expenditures related to OA were being female and having joint stiffness. Conclusion. Despite having heavily subsidized health care and access to the Pharmaceutical Benefits Scheme, out-of-pocket costs for patients with OA in Australia are considerable. Higher expenditures for patients with OA are related to more advanced disease, especially for women.

Stem cells in the aetiopathogenesis and therapy of rheumatic disease

Animal models of autoimmune disease and case reports of patients with these diseases who have been involved in bone marrow transplants have provided important data implicating the haemopoietic stem cell in rheumatic disease pathogenesis. Animal and human examples exist for both cure and transfer of rheumatoid arthritis, systemic lupus erythematosus (SLE) and other organ-specific diseases using allogeneic haemopoietic stem cell transplantation. This would suggest that the stem cell in these diseases is abnormal and could be cured by replacement of a normal stem cell although more in vitro data are required in this area. Given the morbidity and increased mortality in some patients with severe autoimmune diseases and the increasing safety of autologous haemopoietic stem cell transplantation (HSCT), pilot studies have been conducted using HSCT in rheumatic diseases. It is still unclear whether an autologous graft will cure these diseases but significant remissions have been obtained which have provided important data for the design of randomized trials of HSCT versus more conventional therapy. Several trials are now open to accrual under the auspices of the European Bone Marrow Transplant Group/European League Against Rheumatism (EBMT/EULAR) registry. Future clinical and laboratory research will need to document the abnormalities of the stem cell of a rheumatic patient because new therapies based on gene therapy or stem cell differentiation could be apllied to these diseases. With increasing safety of allogeneic HSCT it is not unreasonable to predict cure of some rheumatic diseases in the near future.

Determinants of death following burn injury

Background: Burn care has changed considerably. Early surgery, nutritional support, improved resuscitation and novel skin replacement techniques are now well established. The aim of the study was to establish whether changes in management have improved survival following burn injury and to determine the contributory factors leading to non-survival. Methods: This was a retrospective outcome analysis of data collected from a consecutive series of 4094 patients with burns admitted to a tertiary referral, metropolitan teaching hospital between 1972 and 1996, Results: The overall mortality rate was 3.6 per cent. This decreased from 5.3 per cent (1972-1980) to 3.4 per cent (1993-1996) (P = 0.076). The risk of death was increased with increasing burn size (relative risk (RR) 95.90 (95 per cent confidence interval 12.60-729.47) if more than 35 per cent of the total body surface area was burned; P < 0.001) increasing age (RR 7.32 (3.08-17.42) if aged more than 48 years; P < 0.001), inhalation injury (RR 3.61 (2.39-5.47); P < 0.001) and female sex (RR 1.82 (1.23-2.69); P = 0.003). Operative intervention (RR 0.11 (0.06-0.21); P < 0.001) and the presence of an upper limb burn (RR 0.53 (0.35-0.79); P = 0.002) decreased the risk. Conclusion: Modern burn care has decreased the mortality rate. Increasing burn size, increasing age, inhalation injury and female sex increased, while operative intervention and an upper limb burn decreased, the risk of death.

Replacing prelinguistic behaviors with functional communication

This study evaluated the effectiveness of a teacher-implemented intervention package designed to replace prelinguistic behaviors with functional communication. Four young children with autism participated in a multiple-probe design across three communicative functions. Initially, three existing communication functions were selected for each child. Next, the existing prelinguistic behaviors that the children used to achieve these functions were identified. Replacement forms that were considered more recognizable and symbolic were defined to achieve these same functions. After a baseline phase, teachers received inservice training, consultation, and feedback on how to encourage, acknowledge, and respond to the replacement forms. During intervention, the replacement forms increased and prelinguistic behaviors decreased in most cases. The results suggested that the teacher-implemented intervention was effective in replacing prelinguistic behaviors with alternative forms of functional communication.

Pharmacokinetics of ciprofloxacin in ICU patients on continuous veno-venous haemodiafiltration

Objectives: To investigate the pharmacokinetics of intravenous ciprofloxacin 200 mg every 8 h in critically ill patients on continuous veno-venous haemodiafiltration (CVVHDF), one form of continuous renal replacement therapy (CRRT). Design and setting: Open, prospective clinical study in a multidisciplinary, intensive care unit in a university-affiliated tertiary referral hospital. Patients: Sis critically ill patients with acute renal failure on CVVHDF. Interventions: Timed blood and ultrafiltrate samples were collected to allow pharmacokinetics and clearances to be calculated of initial and subsequent doses of 200 mg intravenous ciprofloxacin. CVVHD was performed with 1 l/h of dialysate and 2 l/h of predilution filtration solution, producing 3 lih of dialysis effluent. The blood was pumped at 200 ml/min using a Gambro BMM-10 blood pump through a Hospal AN69HF haemofilter,. Measurements and results: Ten pharmacokinetic profiles were measured. The CVVHDF displayed a urea clearance of 42 +/- 3 ml/min, and removed ciprofloxacin with a clearance of 37 +/- 7 ml/min. This rate was 2-2.5 greater than previously published for ciprofloxacin in other forms of CRRT. On average the CVVHDF was responsible for clearing a fifth of all ciprofloxacin eliminated (21 +/- 10%). The total body clearance of ciprofloxacin was 12.2 +/- 4.3 l/h. The trough concentration following the initial dose was 0.7 +/- 0.3 mg/l. The area under the plasma concentration time curves over a 24-h period ranged from 21 to 55 mg .h l(-1). Conclusions: Intravenous ciprofloxacin 600 mg/day in critically ill patients using this form of CRRT produced adequate plasma levels for many resistant microbes found in intensive care units.

Outcomes of transient evoked otoacoustic emission testing in 6-year-old school children: A comparison with pure tone screening and tympanometry

Objectives: (1) To establish test performance measures for Transient Evoked Otoacoustic Emission testing of 6-year-old children in a school setting; (2) To investigate whether Transient Evoked Otoacoustic Emission testing provides a more accurate and effective alternative to a pure tone screening plus tympanometry protocol. Methods: Pure tone screening, tympanometry and transient evoked otoacoustic emission data were collected from 940 subjects (1880 ears), with a mean age of 6.2 years. Subjects were tested in non-sound-treated rooms within 22 schools. Receiver operating characteristics curves along with specificity, sensitivity, accuracy and efficiency values were determined for a variety of transient evoked otoacoustic emission/pure tone screening/tympanometry comparisons. Results: The Transient Evoked Otoacoustic Emission failure rate for the group was 20.3%. The failure rate for pure tone screening was found to be 8.9%, whilst 18.6% of subjects failed a protocol consisting of combined pure tone screening and tympanometry results. In essence, findings from the comparison of overall Transient Evoked Otoacoustic Emission pass/fail with overall pure tone screening pass/fail suggested that use of a modified Rhode Island Hearing Assessment Project criterion would result in a very high probability that a child with a pass result has normal hearing (true negative). However, the hit rate was only moderate. Selection of a signal-to-noise ratio (SNR) criterion set at greater than or equal to 1 dB appeared to provide the best test performance measures for the range of SNR values investigated. Test performance measures generally declined when tympanometry results were included, with the exception of lower false alarm rates and higher positive predictive values. The exclusion of low frequency data from the Transient Evoked Otoacoustic Emission SNR versus pure tone screening analysis resulted in improved performance measures. Conclusions: The present study poses several implications for the clinical implementation of Transient Evoked Otoacoustic Emission screening for entry level school children. Transient Evoked Otoacoustic Emission pass/fail criteria will require revision. The findings of the current investigation offer support to the possible replacement of pure tone screening with Transient Evoked Otoacoustic Emission testing for 6-year-old children. However, they do not suggest the replacement of the pure tone screening plus tympanometry battery. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.

The ratio of messenger RNA levels of receptor activator of nuclear factor kappa B ligand to osteoprotegerin correlates with bone remodeling indices in normal human cancellous bone but not in osteoarthritis

skeletal disease. Bone remodeling is initiated by osteoclastic resorption followed by osteoblastic formation of new bone. Receptor activator of nuclear factor KB ligand (RANKL) is a newly described regulator of osteoclast formation and function, the activity of which appears to be a balance between interaction with its receptor RANK and with an antagonist binding protein osteoprotegerin (OPG). Therefore, we have examined the relationship between the expression of RANKL, RANK, and OPG and indices of bone structure and turnover in human cancellous bone from the proximal femur. Bone samples were obtained from individuals with osteoarthritis (OA) at joint replacement surgery and from autopsy controls. Histomorphometric analysis of these samples showed that eroded surface (ES/BS) and osteoid surface (OS/BS) were positively associated in both control (p < 0.001) and OA (p < 0.02), indicating that the processes of bone resorption and bone formation remain coupled in OA, as they are in controls. RANKL, OPG, and RANK messenger RNA, (mRNA) were abundant in human cancellous bone, with significant differences between control and OA individuals. In coplotting the molecular and histomorphometric data, strong associations were found between the ratio of RANKL/OPG mRNA and the indices of bone turnover (RANKL/OPG vs. ES/BS: r = 0.93, p < 0.001; RANKL/OPG vs. OS/BS: r = 0.80, p < 0.001). These relationships were not evident in trabecular bone from severe OA, suggesting that bone turnover may be regulated differently in this disease. We propose that the effective concentration of RANKL is related causally to bone turnover.