The influence of gender and body characteristics on upright stance

BACKGROUND

Morphologic characteristics such as height and body weight determine body inertia, an important factor related to postural stability. However, whilst investigations have classically analysed these parameters separately, global morphology has been poorly researched. Secondly, the influence of gender on postural stability demonstrates opposing trends, some authors observing that men sway less than women, and others noting the contrary.

AIM

The aims of this study are to evaluate morphology and gender effects on healthy subjects during postural maintenance.

SUBJECTS AND METHODS

The studied subjects were categorized through the Livi index. A method associating frequential and Brownian parameters characterized the horizontal displacements of the centre of gravity (CG(h)) and those of the difference between the centre of pressure (CP) and the vertical projection of the centre of gravity (CP-CG(v)) separately. Moreover, the moments of body inertia (MI) and natural body frequency (NBF) were also used to determine the influence of morphology.

RESULTS AND CONCLUSIONS

The results reveal that thinner subjects have larger CG(h) displacements than normal or corpulent subjects. Morphologic characteristics (NBF) can explain these behavioural differences. On the other hand, men have a larger sway amplitude for CG(h) motions than women. This can be explained by both morphologic (MI, NBF) and physiological (architectural properties of the soleus muscle) characteristics.

How old is that child? Validating the accuracy of age assignments in observational surveys of vehicle restraint use

OBJECTIVES

Many large scale observational studies of child restraint usage require observers to estimate the ages of the vehicle occupants. The accuracy of age assignments were assessed and possible methods to improve observational accuracy in research and field studies of child restraint use were identified.

METHODS

The validation study was performed at fast food restaurants in a metropolitan area. Three, two person teams observed 449 occupants of vehicles with at least one child passenger. The drivers were then interviewed to obtain the actual ages of the vehicle occupants. The primary outcome measure was the per cent of age assignments that were correct by age category (infant, toddler, school age, teen, adult). The observers had previously conducted a statewide child restraint observation study and were trained in estimating age categories.

RESULTS

A total of 391 (87%) of the 449 occupants were assigned to their correct age categories. Incorrect assignments were more common among infants (22% incorrect), but few infants (nine) were observed. The most frequent error was classifying adults (19 years and older) as teenagers (13-18 years).

CONCLUSION

Trained, experienced observers approached 90% accuracy in their assignment of children to specific age categories. Additional study is required to determine whether these results are applicable to different age categories and observers. It is recommended that the National Highway Traffic Safety Administration, the Centers for Disease Control and Prevention, state and local agencies, and other sponsors of observational surveys consider observer competence as an important variable. The validity of age assignments can be assessed by randomly interviewing a sample of drivers. More accurate age estimates will improve decisions regarding prevention programs, funding, and policies.

Single-strand conformation polymorphism-based analysis reveals genetic variation within Spirometra erinacei (Cestoda: Pseudophyllidea) from Australia

This study examined genetic variability within Spirometra erinacei (Cestoda: Pseudophyllidea) from different host species and geographical origins in Australia using a polymerase chain reaction (PCR)-based mutation detection approach, followed by DNA sequencing. Part of the cytochrome c oxidase subunit 1 gene (p cox 1) was amplified by PCR, scanned for sequence variation by single-strand conformation polymorphism (SSCP), and representative samples from different host species were selected for DNA sequencing. While no variation in SSCP profiles was detected among S. erinacei samples from dog, fox, cat, tiger snake and python, they differed in profile from 5 specimens from the green tree frog (Litoria caerulea). This was supported by sequence data which demonstrated that p cox 1 sequences of samples from the latter host species differed at 8 of 393 (2%) nucleotide positions from those from the non-amphibian host. Using a nucleotide difference in the p cox 1 sequence, a PCR-linked restriction fragment length polymorphism (RFLP) could be employed to unequivocally delineate between samples from non-amphibian and amphibian hosts. These findings demonstrate the existence of at least two genotypes within S. erinacei, which may have important implications for studying the epidemiology, ecology and systematics of this cestode.

Backward and forward leaning postures modelled by an fBm framework

Body leaning effects on postural control have been assessed by recording the centre of pressure (CP) displacements in healthy subjects under three experimental conditions (REF, BWD and FWD corresponding to upright, backward leaning and forward leaning of the body, respectively). The CP displacements were used to compute the motions of the vertical projections of the centre of gravity (CG(v)) and those of the difference CP-CG(v). A frequential analysis shows that the main effect takes place on CP-CG(v) motions, suggesting increased muscular activity in these leaning postures. In addition, changes also occur on CG(v) motions, especially in the antero-posterior (AP) direction. Modelling these motions as fractional Brownian motion (fBm) indicates that leaning the body induces, in the AP direction, a shift in the time interval Deltat at which the corrective process takes over the initial one operating in open-loop. In FWD and BWD conditions, the Deltat is diminished whilst the mean distance covered at this Deltat is increased for both CG(v) and CP-CG(v) motions. Moreover, more determinism in the overall upright stance control is observed in the corrective (closed-loop) process involving CG(v) motions. These facts emphasize the inability for the CP displacements to express properly the overall body sway in upright stance control.

Delayed penile replantation after prolonged warm ischemia

We report a case of microsurgical replantation of traumatic self-amputation of penis after prolonged warm ischemia as a result of delayed presentation. At 12 weeks postoperative follow-up evaluation, the patient exhibited good urinary flow, spontaneous erection, and a normal response to pharmacological stimulation.

The androgen-conjugating uridine diphosphoglucuronosyltransferase-2B enzymes are differentially expressed temporally and spatially in the monkey follicle throughout the menstrual cycle

UDP-glucuronosyltransferase (UGT) enzymes enhance the polarity of steroid hormones by catalyzing their conjugation with the sugar group from UDP-glucuronic acid. Previous results have shown that the monkey is a suitable animal model to study steroid glucuronidation in steroid target tissues. In humans, as in the monkey, the main androgen metabolites found in the circulation are 5alpha-androstane-3alpha,17beta-diol-glucuronide and androsterone glucuronide, and high levels of androsterone glucuronide were also measured in human follicular fluid. Ovarian androgens play a significant role as precursors for estrogens and may modulate the recruitment and growth of follicles. To analyze the expression pattern of UGT2B enzymes involved in androgen metabolism throughout the menstrual cycle, cynomolgus monkey ovaries were collected during the mid and late follicular and luteal phases. Microsomal proteins and total RNA were analyzed for UGT2B expression in the whole ovary. Western blot and specific RT-PCR analyses demonstrated no significant changes in the expression of UGT2B protein or transcripts during the menstrual cycle. Immunocytochemistry analysis showed that UGT2B proteins are expressed in the cytoplasm of thecal and granulosa cells of growing follicles. Interestingly, the thecal cells of secondary follicles and of corpus luteum were extensively stained, whereas luteal granulosa cells were not labeled. These results suggest an important regulation of cell type-specific UGT2B expression during follicular development. Previous results demonstrated similar changes in the expression of the androgen receptor. The colocalization of the androgen receptor and UGT2B enzymes in the same cell types of the ovary provide evidence for a potential role of glucuronidation as a modulator of the intracellular androgen response during follicular development.

Stw 441/465: a new fragmentary ilium of a small-bodied Australopithecus africanus from Sterkfontein, South Africa

In 1986 and 1987, a hominid left ilium fragment consisting of a spina iliaca anterior superior and crista iliaca was discovered during excavations at Sterkfontein, South Africa. Although the specimen is small it gives valuable hints for muscle insertions and origins at the pelvis of Australopithecus africanus. It indicates that the anatomy of the abdominal muscles and of the mm. glutei medius et minimus of A. africanus was quite different from that of the great apes and more similar to that of modern humans. This has major implications for the interpretation of the bipedalism and locomotor efficiency of the early South African hominids.

[Chytridiomycosis in amphibians--first report in Europe]

Declining of amphibian populations is a worldwide phenomenon. A cutaneous mycosis as a cause of death in free-living amphibians as well as in captive ones due to an chytrid fungus (Batrachochytrium dendrobatidis) was reported at first in 1998. This infections were reported hitherto from Australia, North, Central and South America. This is the first report on chytrid infections in captive anurans from Europe. Dendrobates auratus and D. pumilo imported from Costa Rica and P. vittatus imported from French Guayana died with chytridiomycosis within a week after arrival in Europe. Batrachocytrium was also found on captive bred frogs in Germany and Belgium. Clinical signs, diagnosis and conclusions for protecting free-living amphibian populations and captive frogs are discussed.

Using the PerioChip in treating adult periodontitis: an interim report

Multicenter clinical trials have established that the adjunctive use of the subgingival controlled release of chlorhexidine, in the form of the PerioChip, significantly reduces pocket probing depth, improves probing attachment levels, and reduces bleeding on probing compared to scaling and root planing alone, for periods up to 9 months. The purpose of the present study was to report on the adjunctive use of the PerioChip for the long-term management of adult periodontitis for 2 years. A total of 836 patients with adult periodontitis from private dental offices were recruited into the trial. This interim report is on the first 72 patients to have completed the 2-year study. Treatments included initial definitive therapy followed by PerioChip placement in pocket sites with a pocket probing depth of > or = 5 mm after 1 month. Subsequently, the patients received routine periodontal maintenance therapy together with the placement of a PerioChip in pockets with pocket probing depths > or = 5 mm every 3 months. Results indicated that there was a continuous decrease in pocket probing depth over the 2 years (1.26 +/- 0.77 mm). This decrease in pocket probing depth was marked over the first 9 to 12 months, and then appeared to be less marked over the next 12 months. At 2 years, 60% of the patients had at least 2 pockets showing a reduction of 2 mm or more, and only 10% of the patients showed no change or increased pocket probing depth. The results indicate that adjunctive PerioChip use is a clinically effective treatment option for dental professionals and their patients for the long-term management of adult periodontitis.

[Alpha interferon-induced eczema in atopic patients infected by hepatitis C virus: 4 case reports]

OBJECTIVES

We report four cases of eczema induced by alpha interferon in atopic patients treated for chronic hepatitis C.

CASE REPORTS

Eczema developed in 4 patients with certain (3 cases) or possible (1 case) atopy treated by subcutaneous injections of alpha interferon for hepatitis C virus infections. Delay to onset was 3 weeks to 6 months. Interferon was highly likely the causal agent: lesions started at site of interferon injection, followed the rhythm of interferon injections (three cases), disappeared at interferon withdrawal. In two patients, the lesions diffused to other sites. Both Introna and Roféron were used. Three patients also took ribavirine. The possible role of a contact factor (antiseptic.) was ruled out. Skin tests (patch tests, prick tests, intradermal reactions) were negative for interferon alpha and for a standard battery.

DISCUSSION

The role of interferon in the induction of skin diseases or its influence on the course of certain dermatoses is well known. In atopic patients, interferon might induce eczema via an immunomodulator rather than an allergic mechanism since skin tests (performed in one patient) were negative. This observation is similar to that in psoriasis induced by interferon in predisposed subjects who develop skin lesions at injection sites which sometimes diffuse to distant localizations. The role of other factors (hepatitis C virus infection, ribavirine) remains unknown; they might participate in this mechanism by aggravating skin dryness.

DAR, a new RhD variant involving exons 4, 5, and 7, often in linkage with ceAR, a new Rhce variant frequently found in African blacks

The highly polymorphic Rh system is encoded by 2 homologous genes RHD and RHCE. Gene rearrangements, deletions, or point mutations may cause partial D and CE antigens. In this study, a new RHD variant, DAR, and a new RHCE variant, ceAR, are described in 4 Dutch African Blacks. Serologically, DAR showed weaker reactions with a monoclonal antibody and polyclonal antiserum against D. The DAR phenotype was characterized by complete loss of at least 9 of 37 Rh D epitopes. Erythrocytes expressing ceAR were all typed as VS(-), V(+). DNA analysis showed a partial D allele with only 3 mutations: C602G (exon 4), T667G (exon 5), and T1025C (exon 7). The ceAR allele carried G48C (exon 1), a hybrid exon 5 (A712G, C733G, A787G, and T800A), and A916G (exon 6). To study the frequency of these variants, 326 South-African Blacks was screened genomically. Of the 326 donors, 16 (4.9%) carried the DAR allele, 20 (6.1%) the ceAR allele, and 14 (4.3%) both mutated alleles. Five of these donors (1.5%) had the DAR phenotype, indicating that they carried the DAR allele homozygously or next to a D-negative allele. Immunogenicity of the D antigen for individuals with the DAR phenotype was proven, because 1 of the 4 Dutch individuals produced allo-antibodies against D after multiple transfusions with D-positive blood. In a multiethnic society, the prevalence of this D phenotype will increase and is therefore relevant in transfusion practice and in prevention of hemolytic disease of the newborn.

Chlamydia pneumoniae in a free-ranging giant barred frog (Mixophyes iteratus) from Australia

The koala biovar of Chlamydia pneumoniae was identified in lung tissue from a sick, free-ranging giant barred frog (Mixophyes iteratus) by using electron microscopy, C. pneumoniae-specific fluorescent-antibody staining, cell culture, and sequencing of the ompA, ompB and 16S rRNA genes. This is the first report of a chlamydial strain infecting both a homeotherm and a poikilotherm and only the fourth host (in addition to humans, koalas, and horses) to be naturally infected with this species of Chlamydia. The frog had severe, chronic, mononuclear pneumonia and nonregenerative anemia and pancytopenia.

Fli-1, an Ets-related transcription factor, regulates erythropoietin-induced erythroid proliferation and differentiation: evidence for direct transcriptional repression of the Rb gene during differentiation

Erythropoietin (Epo) is a major regulator of erythropoiesis that alters the survival, proliferation, and differentiation of erythroid progenitor cells. The mechanism by which these events are regulated has not yet been determined. Using HB60, a newly established erythroblastic cell line, we show here that Epo-induced terminal erythroid differentiation is associated with a transient downregulation in the expression of the Ets-related transcription factor Fli-1. Constitutive expression of Fli-1 in HB60 cells, similar to retroviral insertional activation of Fli-1 observed in Friend murine leukemia virus (F-MuLV)-induced erythroleukemia, blocks Epo-induced differentiation while promoting Epo-induced proliferation. These results suggest that Fli-1 modulates the response of erythroid cells to Epo. To understand the mechanism by which Fli-1 regulates erythropoiesis, we searched for downstream target genes whose expression is regulated by this transcription factor. Here we show that the retinoblastoma (Rb) gene, which was previously shown to be involved in the development of mature erythrocytes, contains a Fli-1 consensus binding site within its promoter. Fli-1 binds to this cryptic Ets consensus site within the Rb promoter and transcriptionally represses Rb expression. Both the expression level and the phosphorylation status of Rb are consistent with the response of HB60 cells to Epo-induced terminal differentiation. We suggest that the negative regulation of Rb by Fli-1 could be one of the critical determinants in erythroid progenitor cell differentiation that is specifically deregulated during F-MuLV-induced erythroleukemia.

Localization of type 5 17beta-hydroxysteroid dehydrogenase, 3beta-hydroxysteroid dehydrogenase, and androgen receptor in the human prostate by in situ hybridization and immunocytochemistry

An important source of androgens in the human prostate are those synthesized locally from the inactive adrenal precursor dehydroepiandrosterone (DHEA) and its sulfated derivative DHEA-S. Three beta-HSD (hydroxysteroid dehydrogenase) converts DHEA into androstenedione (4-dione), whereas type 5 17beta-HSD catalyzes the reduction of 4-dione into testosterone in the human prostate and other peripheral intracrine tissues. In the present study, we have used two complementary approaches, namely in situ hybridization and immunocytochemistry, to identify the cells that contain the type 5 17beta-HSD messenger RNA and enzyme in human benign prostatic hyperplasia (BPH). Localization of 3beta-HSD and of the androgen receptor (AR) was also investigated by immunostaining in the same tissue. To find out whether there are any differences between BPH and normal prostate tissue, the localization of type 5 17beta-HSD was reexamined by immunocytochemistry in the normal human prostate samples and also in normal prostate epithelial cell line (PrEC). The in situ hybridization results obtained with a tritiated uridine triphosphate (3H-UTP)-labeled type 5 17beta-HSD riboprobe are in agreement with the immunostaining data obtained with a specific antibody to the enzyme. The immunostaining results obtained from normal prostate tissue and BPH were found to be similar. Thus, in the glandular epithelium, basal cells highly express the messenger RNA and the enzyme, whereas luminal cells show a much lower and variable level of expression. In the stroma and walls of blood vessels, fibroblasts and the endothelial cells lining the blood vessels show positive staining. Similar results are observed when the cellular distribution of 3beta-HSD is investigated. AR immunoreactivity, however, shows a different distribution because, in the epithelium, most of the nuclei of basal cells are negative, whereas the majority of nuclei of the luminal cells show positive staining. A strong reaction for AR is also found in most stromal cell nuclei and in the nuclei of most endothelial cells, as well as in some other cells of the walls of blood vessels. In conclusion, human type 5 17beta-HSD, as well as 3beta-HSD, are highly expressed, not only in the basal epithelial cells and stromal fibroblasts but also in the endothelial cells and fibroblasts of the blood vessels. AR, on the other hand, is highly expressed in the luminal cells. The present data suggest that DHEA is transformed in the basal cells of the glandular epithelium into 4-dione by 3beta-HSD and then into testosterone by type 5 17beta-HSD, whereas dihydrotestosterone is synthesized in the luminal cells after diffusion of testosterone from the underlying layer of basal cells. The potential role of androgen formation and action in blood vessels is unknown and opens new avenues of investigation for a better understanding of the multiple roles of androgens.

Emerging infectious diseases and amphibian population declines

We review recent research on the pathology, ecology, and biogeography of two emerging infectious wildlife diseases, chytridiomycosis and ranaviral disease, in the context of host-parasite population biology. We examine the role of these diseases in the global decline of amphibian populations and propose hypotheses for the origins and impact of these panzootics. Finally, we discuss emerging infectious diseases as a global threat to wildlife populations.

Chytridiomycosis causes amphibian mortality associated with population declines in the rain forests of Australia and Central America

Epidermal changes caused by a chytridiomycete fungus (Chytridiomycota; Chytridiales) were found in sick and dead adult anurans collected from montane rain forests in Queensland (Australia) and Panama during mass mortality events associated with significant population declines. We also have found this new disease associated with morbidity and mortality in wild and captive anurans from additional locations in Australia and Central America. This is the first report of parasitism of a vertebrate by a member of the phylum Chytridiomycota. Experimental data support the conclusion that cutaneous chytridiomycosis is a fatal disease of anurans, and we hypothesize that it is the proximate cause of these recent amphibian declines.

Lyssaviral infection and lead poisoning in black flying foxes from Queensland

Pteropid lyssaviral infection, lead poisoning, and the difficulties in diagnosing pteropid lyssaviral infection using histopathological examination of tissues are described in wild black flying foxes (Pteropus alecto) from northern Queensland (Australia). An adult female P. alecto showed aggression before death in January 1995. Lead poisoning was diagnosed due to the presence of intranuclear lead inclusion bodies in renal proximal convoluted tubular epithelium and high concentrations of lead in renal and hepatic tissues, 370.03 +/- 7.35 ppm and 16.76 +/- 0.53 ppm, respectively. Renal inclusion bodies were composed of lead, calcium, phosphorus, and possibly sulphur; some inclusions had their granules arranged in concentric bands. This bat also had a moderate concentration (8.09 +/- 0.18 ppm) of cadmium in renal tissue. An adult male P. alecto presented with ascending paralysis before it died in May 1996. Pteropid lyssaviral infection was diagnosed subsequently in both bats in September 1996 by immunofluorescent and immunoperoxidase antibody tests for rabies on brains and viral culture from brains. Neither bat had gross or microscopic lesions of the brain that suggested a lyssaviral infection, apart from occasional, subtle, eosinophilic cytoplasmic inclusions in the neurones of the brain stem of the female. These cases illustrate the need for a specific test to detect pteropid lyssavirus such as an immunofluorescent antibody test for lyssavirus rather than histopathological examination of tissues.