In the past three decades, mounting evidence has revealed that specification of the basic cortical neuronal classes starts at the time of their final mitotic divisions in the embryonic proliferative zones. This early cell determination continues during the migration of the newborn neurons across the widening cerebral wall, and it is in the cortical plate that they attain their final positions and establish species-specific cytoarchitectonic areas. Here, the development and evolutionary expansion of the neocortex is viewed in the context of the radial unit and protomap hypotheses. A broad spectrum of findings gave insight into the pathogenesis of cortical malformations and the biological bases for the evolution of the modern human neocortex. We examine the history and evidence behind the concept of early specification of neurons and provide the latest compendium of genes and signaling molecules involved in neuronal fate determination and specification.

The third variable region (V3) of the HIV-1 surface glycoprotein, gp120, plays a central role in the interaction of the virus envelope with the cell surface chemokine receptors, triggering membrane fusion and virus entry into human lymphocytes and macrophages. The CXCR4 and CCR5 chemokine receptors are used by "X4-tropic" and "R5-tropic" viruses, respectively. Recently, the crown of the V3 loop was shown to bear a close structural homology to the beta2-beta3 loop in the CXC and CC chemokines, the natural ligands of CXCR4 and CCR5, respectively. This homology can serve as the foundation for 3D molecular modeling of the V3 loops from primary isolates whose coreceptor usage was experimentally defined. The modeling revealed a charged "patch" on the surface of V3 that correlates with coreceptor usage. This V3 surface patch is positively charged in X4-tropic viruses and negatively charged or neutral in R5-tropic viruses, and is formed by two amino acids, at position 11 and at position 24 or 25; amino acids 11 and 24 or 11 and 25 contact each other in 3D space. Residues at positions 11 and 25 were known previously to influence coreceptor usage, and the charge of the residues at these two positions is often used to predict viral tropism. However, we found that the predictive value of using the charge of residues 11, 24, and 25 to identify X4 or R5 tropism was improved over using only the charge of residues 11 and 25. Thus, the data suggest a new " 11/24/25 rule" : a positively charged amino acid at position 11, 24, or 25 defines X4; otherwise R5. This rule gave an overall predictive value of 94% for 217 viruses whose tropism had been determined experimentally as either X4 or R5. The results have additional implications for the design of HIV therapeutics, vaccines, and strategies for monitoring disease progression.

When pilus+ Gc were introduced into a male subject's urethra, they gave rise to pilus+ variants whose pilin mRNAs differed from that of input Gc. The differences stemmed from the Gc genome's single complete pilin gene having undergone gene conversion by different partial pilin genes' sequences and by different length stretches of a single partial pilin gene. In some instances, the variant's pilin mRNA appeared to reflect two independent gene-conversion events that used sequences from two different partial pilin genes. The resulting variants' pilins exhibited antigenic differences compared with the pilin polypeptide of input Gc; these differences were discernible by immunoblotting with mAbs. Amino acid and antigenic changes occurred in a segment of the variants' pilin polypeptides that previously was thought to be conserved or constant in sequence.

Previous investigations in various motor and sensory cortical areas have shown that fast oscillations (20-80 Hz) of focal electroencephalogram and multiunit activities occur spontaneously during increased alertness or are dependent upon optimal sensory stimuli. We now report the presence of 20- to 40-Hz rhythmic activities in intracellularly recorded thalamocortical cells of the cat. In some neurons, subthreshold oscillations were triggered by depolarizing pulses and eventually gave rise to action potentials. In other neurons, the oscillations consisted of fast prepotentials, occasionally generating full spikes that arose from the resting or even from hyperpolarized membrane potential levels, and leading to trains of spikes at more depolarized levels. The rhythmic nature of these fast prepotentials was confirmed by means of an autocorrelation study, which demonstrated clear peaks at 25-ms intervals (40 Hz). In view of the recent evidence that mesopontine cholinergic nuclei trigger and maintain activation processes in thalamocortical systems, we tested the possibility that stimulation of these brainstem nuclei potentiates the 40-Hz waves on the background of the cortical electroencephalogram. This was indeed the case. The potentiation outlasted the stimulation by 10-20 s. The brainstem-induced facilitation of cortical 40-Hz oscillations was blocked by scopolamine, a muscarinic antagonist. That this facilitation was transmitted by brainstem-thalamic cholinergic projections was confirmed by persistence of the phenomenon after large excitotoxic lesions of the nucleus basalis of Meynert.

We used an in vitro assay system based on HeLa cell core transcription components to examine transcript elongation by RNA polymerase II on either naked DNA or chromatin templates as a function of the three known elongation factors, IIS, TFIIF, and TFIIX. We demonstrate for the first time that mammalian RNA polymerase II can achieve physiological elongation rates on naked DNA templates in vitro. The addition of TFIIF alone gave this rate, although IIS was required to minimize the block to elongation at intrinsic termination sites. However, IIS and TFIIF provided only a slight increase in the very poor elongation efficiency of RNA polymerase II on chromatin templates. The addition of TFIIX to reactions containing IIS and TFIIF reduced the elongation rate on naked DNA templates but slightly increased the elongation efficiency on chromatin. The ability of elongation factors either separately or in combination to stimulate transcription on naked DNA and chromatin templates was also examined.

In oncological research, there is a great need for imaging techniques that specifically identify angiogenic blood vessels in tumors on the basis of differences in the expression level of biomolecular markers. In the angiogenic cascade, different cell surface receptors, including the alphavbeta3-integrin, are strongly expressed on activated endothelial cells. In the present study, we aimed to image angiogenesis by detecting the expression of alphavbeta3 in tumor bearing mice with a combination of magnetic resonance imaging (MRI) and fluorescence microscopy. To that end, we prepared MR-detectable and fluorescent liposomes, which carry approximately 700 alphavbeta3-specific RGD peptides per liposome. RGD competition experiments and RAD-conjugated liposomes were used as controls for specificity. In vivo, both RAD liposomes and RGD liposomes gave rise to signal increase on T1-weighted MR images. It was established by the use of ex vivo fluorescence microscopy that RGD liposomes and RAD liposomes accumulated in the tumor by different mechanisms. RGD liposomes were specifically associated with activated tumor endothelium, while RAD liposomes were located in the extravascular compartment. This study demonstrates that MR molecular imaging of angiogenesis is feasible by using a targeted contrast agent specific for the alphavbeta3-integrin, and that the multimodality imaging approach gave insight into the exact mechanism of accumulation in the tumor.

We report a direct technique for determining the binding sites of small molecules on naturally occurring heterogeneous DNA. Methidiumpropyl-EDTA.Fe(II) [MPE.Fe(II) cleaves double helical DNA with low sequence specificity. Using a combination of MPE.Fe(II) cleavage of drug-protected DNA fragments and Maxam-Gilbert gel methods of sequence analysis, we have determined the preferred binding sites on a Rsa I-EcoRI restriction fragment from pBR322 for the intercalator actinomycin D and the minor groove binders netropsin and distamycin A. Netropsin and distamycin A gave identical DNA cleavage-inhibition patterns and bound preferentially to A+T-rich regions with a minimal protected site of four base pairs. We were able to observe the effect of increasing concentration on site selection by netropsin and distamycin A. Actinomycin D afforded a completely different cleavage-inhibition pattern, with 4- to 16-base-pair-long protected regions centered around one or more G.C base pairs.

OBJECTIVE

To assess the evidence for the acceptability and effectiveness of screening women for domestic violence in healthcare settings.

METHODS

Systematic review of published quantitative studies. SESRCH STRATEGY: Three electronic databases (Medline, Embase, and CINAHL) were searched for articles published in the English language up to February 2001.

METHODS

Surveys that elicited the attitudes of women and health professionals on the screening of women in health settings; comparative studies conducted in healthcare settings that measured rates of identification of domestic violence in the presence and absence of screening; studies measuring outcomes of interventions for women identified in health settings who experience abuse from a male partner or ex-partner compared with abused women not receiving an intervention.

RESULTS

20 papers met the inclusion criteria. In four surveys, 43-85% of women respondents found screening in healthcare settings acceptable. Two surveys of health professionals' views found that two thirds of physicians and almost half of emergency department nurses were not in favour of screening. In nine studies of screening compared with no screening, most detected a greater proportion of abused women identified by healthcare professionals. Six studies of interventions used weak study designs and gave inconsistent results. Other than increased referral to outside agencies, little evidence exists for changes in important outcomes such as decreased exposure to violence. No studies measured quality of life, mental health outcomes, or potential harm to women from screening programmes.

CONCLUSIONS

Although domestic violence is a common problem with major health consequences for women, implementation of screening programmes in healthcare settings cannot be justified. Evidence of the benefit of specific interventions and lack of harm from screening is needed.

Xylan, the major hemicellulosic polysaccharide in Arabidopsis secondary cell walls, requires a number of glycosyltransferases (GT) to catalyse formation of the various glycosidic linkages found in the polymer. In this study, we characterized IRX10 and IRX10-like (IRX10-L), two highly homologous genes encoding members of the glycosyltransferase family 47 (GT47). T-DNA insertions in IRX10 gave a mild irregular xylem (irx) phenotype consistent with a minor defect in secondary cell-wall synthesis, whereas plants containing mutations in IRX10-L showed no change. However, irx10 irx10-L double mutant plants showed a much more severe irx and whole-plant phenotype, suggesting considerable functional redundancy between these two genes. Detailed biochemical analysis of the irx10 irx10-L double mutant showed a large reduction of xylan in the secondary cell walls, consistent with a specific defect in xylan biosynthesis. Furthermore, the irx10 irx10-L mutant retains the unique oligosaccharide found at the reducing end of Arabidopsis xylan, but shows a severe reduction in beta(1,4) xylosyltransferase activity. These characteristics are similar to those of irx9 and irx14, mutants that are believed to be defective in xylan chain elongation, and suggests that IRX10 and IRX10-L also play a role in elongation of the xylan backbone.

The central autonomic network (CAN) has been described in animal models but has been difficult to elucidate in humans. Potential confounds include physiological noise artifacts affecting brainstem neuroimaging data, and difficulty in deriving non-invasive continuous assessments of autonomic modulation. We have developed and implemented a new method which relates cardiac-gated fMRI timeseries with continuous-time heart rate variability (HRV) to estimate central autonomic processing. As many autonomic structures of interest are in brain regions strongly affected by cardiogenic pulsatility, we chose to cardiac-gate our fMRI acquisition to increase sensitivity. Cardiac-gating introduces T1-variability, which was corrected by transforming fMRI data to a fixed TR using a previously published method [Guimaraes, A.R., Melcher, J.R., et al., 1998. Imaging subcortical auditory activity in humans. Hum. Brain Mapp. 6(1), 33-41]. The electrocardiogram was analyzed with a novel point process adaptive-filter algorithm for computation of the high-frequency (HF) index, reflecting the time-varying dynamics of efferent cardiovagal modulation. Central command of cardiovagal outflow was inferred by using the resample HF timeseries as a regressor to the fMRI data. A grip task was used to perturb the autonomic nervous system. Our combined HRV-fMRI approach demonstrated HF correlation with fMRI activity in the hypothalamus, cerebellum, parabrachial nucleus/locus ceruleus, periaqueductal gray, amygdala, hippocampus, thalamus, and dorsomedial/dorsolateral prefrontal, posterior insular, and middle temporal cortices. While some regions consistent with central cardiovagal control in animal models gave corroborative evidence for our methodology, other mostly higher cortical or limbic-related brain regions may be unique to humans. Our approach should be optimized and applied to study the human brain correlates of autonomic modulation for various stimuli in both physiological and pathological states.

The conjugative plasmid pAD1 (56.7 kilobases) in Streptococcus faecalis confers hemolysin-bacteriocin (Hly-Bcn) expression and a mating response to the sex pheromone cAD1 excreted by recipient cells. We examined the contribution of hemolysin to pathogenicity in intraperitoneally infected mice by using Tn916 and Tn917 insertion mutants altered in hemolysin expression. Strains exhibiting the normal hemolysin phenotype were significantly more virulent than the nonhemolytic insertion mutants. A mutant plasmid with an increased copy number which gave rise to a larger-than-normal zone of hemolysis on blood agar rendered host strains more virulent than the wild-type streptococci in mice.

Although epithelial ovarian cancers (EOCs) have been thought to arise from the simple epithelium lining the ovarian surface or inclusion cysts, the major subtypes of EOCs show morphologic features that resemble those of the müllerian duct-derived epithelia of the reproductive tract. We found that HOX genes, which normally regulate mullerian duct differentiation, are not expressed in normal ovarian surface epithelium (OSE), but are expressed in different EOC subtypes according to the pattern of mullerian-like differentiation of these cancers. Ectopic expression of Hoxa9 in tumorigenic mouse OSE cells gave rise to papillary tumors resembling serous EOCs. In contrast, Hoxa10 and Hoxa11 induced morphogenesis of endometrioid-like and mucinous-like EOCs, respectively. Hoxa7 showed no lineage specificity, but promoted the abilities of Hoxa9, Hoxa10 and Hoxa11 to induce differentiation along their respective pathways. Therefore, inappropriate activation of a molecular program that controls patterning of the reproductive tract could explain the morphologic heterogeneity of EOCs and their assumption of müllerian-like features.

Glutathione, NAD, and NADP are key nonprotein redox couples in the aqueous phase of virtually all cells, whereas in plant cells ascorbate also plays an important role in redox homeostasis. This work presents the development and validation of plate reader assays that allow rapid analysis of these four redox couples in extracts of Arabidopsis leaves. Analytical methods were adapted and validated for specific measurement of oxidized and reduced forms. Oxidized and reduced forms of glutathione and ascorbate, as well as NAD(+) and NADP(+), were measured in HCl extracts, NADH, and NADPH in parallel alkaline extracts. Both standards and extracts gave linear assay responses, and recovery quotients of added metabolites through the extraction procedure were generally high. The plate reader method was validated against more conventional spectrophotometric assays and also, for glutathione, by HPLC analysis. The method was shown to yield quantitative data for six independent extracts with a total sample preparation and analysis time of 4h. Analysis of the four redox couples throughout Arabidopsis rosette development showed that redox states were relatively constant but that total pools of NAD, glutathione, and ascorbate were significantly modified by day length and developmental stage.

The adenomatous polyposis coli protein (APC) is mutated in familial adenomatous polyposis patients as well as in sporadic colorectal tumors. In an attempt to further understand the function of APC, the subcellular localization of APC was examined. Wild-type and mutant forms of APC were expressed in mammalian cells and protein detected by immunofluorescence using monoclonal and polyclonal antibodies. Staining of wildtype APC protein revealed a filamentous network which extended throughout the cytoplasm and colocalized with microtubules. In striking contrast, mutant APC protein gave a diffuse cytoplasmic staining pattern. Treatment with a microtubule depolymerizing agent, nocodazole, caused APC as well as tubulin to become diffusely cytoplasmic. In addition, immunoperoxidase staining of transfected APC protein followed by transmission electron microscopy revealed staining of microtubules. These results suggest that wild-type but not mutant APC protein may be associated with the microtubule cytoskeleton.

When freshly isolated rabbit marrow cells were cultured either in vitro or in diffusion chambers in vivo, the hemopoietic cells disappeared and there was a proliferation of the stromal cell population. The colonies formed in vitro were mainly fibroblastic, and this cell type predominated in confluent cultures. Staining for alkaline phosphatase activity and for the Von Kossa reaction was negative in in vitro cultures. However, marrow cell suspensions or fibroblasts harvested from in vitro culture of marrow cells, gave rise to a mixture of bone, cartilage and fibrous tissue in diffusion chambers implanted into the peritoneal cavity. In contrast, only a soft fibrous tissue developed from spleen fibroblasts in diffusion chambers. Differentiation of osteogenic tissue within diffusion chambers fell into two categories: (1) Formation of bone in a fibrous layer surrounding cartilage; (2) intramembranous bone formed directly within fibrous tissue unassociated with cartilage. In both cases alkaline phosphatase activity appeared before the onset of mineralization, and decreased as the first signs of mineral became apparent. The present results suggest that postnatal marrow contains osteogenic precursors with the potential to differentiate via either of the two major paths followed during skeletal development in the embryo. Clonal analysis of the marrow stromal cell population will be required to clarify whether osteo-, chondro-, and fibrogenic cells are the products of one stromal cell line modulated by the microenvironment, or whether there are distinct cell lines for each type.

Liver microsomes, isolated from rats which had been treated with phenobarbital in vivo, were found to exhibit increased activities of oxidative demethylation and TPNH-cytochrome c reductase and an increased amount of CO-binding pigment. Simultaneous administration of actinomycin D or puromycin abolished the phenobarbital-induced enzyme synthesis. Increased rate of P(i) (32) incorporation into microsomal phospholipid was the first sign of phenobarbital stimulation and appeared 3 hours after a single injection of this drug. Microsomes were divided into smooth-surfaced and rough-surfaced vesicle fractions. The fraction consisting of smooth-surfaced vesicles exhibited the greatest increase in protein content and oxidative demethylation activity after phenobarbital administration in vivo. Ultrastructural studies revealed that drug treatment also gave rise to proliferation of the endoplasmic reticulum in the hepatic parenchymal cells, first noticed after two phenobarbital injections. The phenobarbital-induced synthesis of the metabolizing enzymes is discussed with special reference to the relationship to the stimulated synthesis of the endoplasmic membranes.

The mapping out of the histologic distribution of blood group antigens A and B in human tissues was performed by means of the fluorescent antibody technique. Human hyperimmune sera were conjugated with fluorescein isocyanate and applied to frozen sections of human material obtained at autopsy or after surgical removal. The material examined encompassed A, B, and AB subjects. In the latter the anti-A and the anti-B conjugate elicited the same picture. Group O tissues were used for controls and were uniformly negative. The secretor status of subjects was determined from the saliva or by the Lewis typing of erythrocytes. The results fall into the following main divisions: Endothelia of Vessels.-Widespread localization was demonstrated in the cell walls of endothelium of capillaries, veins, arteries, and of sinusoidal cells of spleen. Stratified Epithelia.-These showed good outlining of cells of the Malpighian (and the granular, when present) layers. In transitional epithelia, cells of the basal and contiguous layers gave specific staining. Mucus-Secreting Apparatus.-Positive staining was obtained in glands, goblet cells, and secreting surface epithelia. In non-secretors there was no identifiable antigen with the important exception of the deeper parts of gastric foveolae, deeper parts of crypts of Lieberkühn of bowel mucosa and Brunner's glands of the duodenum. Various Organs of Secretion and Excretion.-The pancreas (exocrine portion) and the sweat glands were found to produce the antigen irrespectively of secretor status. Breast, prostate, and endometrial glands on the other hand apparently secrete the antigen in conformity with the subject's secretor:non-secretor make-up. Thus the secretor:non-secretor status governs principally the antigens associated with mucous secretions and this in most but not all locations. The possible nature of this control is briefly discussed.

We previously observed that the cortical neuronal cell adhesion mediated by midkine (MK), a heparin (Hep)-binding growth factor, is specifically inhibited by oversulfated chondroitin sulfate-E (CS-E) (Ueoka, C., Kaneda, N., Okazaki, I., Nadanaka, S., Muramatsu, T., and Sugahara, K. (2000) J. Biol. Chem. 275, 37407-37413) and that CS-E exhibits neurite outgrowth promoting activities toward embryonic rat hippocampal neurons. We have also shown oversulfated CS chains in embryonic chick and rat brains and demonstrated that the CS disaccharide composition changes during brain development. In view of these findings, here we tested the possibility of CS-E interacting with Hep-binding growth factors during development, using squid cartilage CS-E. The binding ability of Hep-binding growth factors (MK, pleiotrophin (PTN), fibroblast growth factor-1 (FGF-1), FGF-2, Hep-binding epidermal growth factor-like growth factor (HB-EGF), FGF-10, FGF-16, and FGF-18) toward [(3)H]CS-E was first tested by a filter binding assay, which demonstrated direct binding of all growth factors, except FGF-1, to CS-E. The bindings were characterized further in an Interaction Analysis system, where all of the growth factors, except FGF-1, gave concentration-dependent and specific bindings. The kinetic constants k(a), k(d), and K(d) suggested that MK, PTN, FGF-16, FGF-18, and HB-EGF bound strongly to CS-E, in comparable degrees to the binding to Hep, whereas the intensity of binding of FGF-2 and FGF-10 toward CS-E was lower than that for Hep. These findings suggest the possibility of CS-E being a binding partner, a coreceptor, or a genuine receptor for various Hep-binding growth factors in the brain and possibly also in other tissues.

People with severe mental illness have a considerably shorter lifespan than the general population. This excess mortality is mainly due to physical illness. Next to mental illness-related factors, unhealthy lifestyle, and disparities in health care access and utilization, psychotropic medications can contribute to the risk of physical morbidity and mortality. We systematically reviewed the effects of antipsychotics, antidepressants and mood stabilizers on physical health outcomes in people with schizophrenia, depression and bipolar disorder. Updating and expanding our prior systematic review published in this journal, we searched MEDLINE (November 2009 - November 2014), combining the MeSH terms of major physical disease categories (and/or relevant diseases within these categories) with schizophrenia, major depressive disorder and bipolar disorder, and the three major psychotropic classes which received regulatory approval for these disorders, i.e., antipsychotics, antidepressants and mood stabilizers. We gave precedence to results from (systematic) reviews and meta-analyses wherever possible. Antipsychotics, and to a more restricted degree antidepressants and mood stabilizers, are associated with an increased risk for several physical diseases, including obesity, dyslipidemia, diabetes mellitus, thyroid disorders, hyponatremia; cardiovascular, respiratory tract, gastrointestinal, haematological, musculoskeletal and renal diseases, as well as movement and seizure disorders. Higher dosages, polypharmacy, and treatment of vulnerable (e.g., old or young) individuals are associated with greater absolute (elderly) and relative (youth) risk for most of these physical diseases. To what degree medication-specific and patient-specific risk factors interact, and how adverse outcomes can be minimized, allowing patients to derive maximum benefits from these medications, requires adequate clinical attention and further research.

This review article on the degeneration and regeneration of peripheral nerve fibers was presented as a Plenary Lecture at the 2001 meeting of the Peripheral Nerve Society. It is accompanied by a reprint of Augustus Waller's 1850 article, which gave rise to the pathologic process termed Wallerian degeneration. This review is focused on the role of neuroinflammation in Wallerian degeneration and how immune mediators contribute to both axonal degeneration and regeneration. Similarities and differences between the PNS and CNS in terms of inflammation and microglial activation after nerve injury are discussed, and point towards progress in understanding the failure of nerve fiber regeneration in the CNS.

To examine the reasons patients and their relatives take legal action, we surveyed 227 patients and relatives who were taking legal action through five firms of plaintiff medical negligence solicitors. Over 70% of respondents were seriously affected by incidents that gave rise to litigation with long-term effects on work, social life, and family relationships. Intense emotions were aroused and continued to be felt for a long time. The decision to take legal action was determined not only by the original injury, but also by insensitive handling and poor communication after the original incident. Where explanations were given, less than 15% were considered satisfactory. Four main themes emerged from the analysis of reasons for litigation: concern with standards of care--both patients and relatives wanted to prevent similar incidents in the future; the need for an explanation--to know how the injury happened and why; compensation--for actual losses, pain and suffering or to provide care in the future for an injured person; and accountability--a belief that the staff or organisation should have to account for their actions. Patients taking legal action wanted greater honesty, an appreciation of the severity of the trauma they had suffered, and assurances that lessons had been learnt from their experiences. A no-fault compensation system, however well intended, would not address all patients' concerns. If litigation is viewed solely as a legal and financial problem, many fundamental issues will not be addressed or resolved.

The epithelial architecture of the thymus fosters growth, differentiation, and T cell receptor repertoire selection of large numbers of immature T cells that continuously feed the mature peripheral T cell pool. Failure to build or to maintain a proper thymus structure can lead to defects ranging from immunodeficiency to autoimmunity. There has been long-standing interest in unraveling the cellular and molecular basis of thymus organogenesis. Earlier studies gave important morphological clues on thymus development. More recent cell biological and genetic approaches yielded new and conclusive insights regarding the germ layer origin of the epithelium and the composition of the medulla as a mosaic of clonally derived islets. The existence of epithelial progenitors common for cortex and medulla with the capacity for forming functional thymus after birth has been uncovered. In addition to the thymus in the chest, mice can have a cervical thymus that is small, but functional, and produces T cells only after birth. It will be important to elucidate the pathways from putative thymus stem cells to mature thymus epithelial cells, and the properties and regulation of these pathways from ontogeny to thymus involution.

We did a retrospective study of all anterior cruciate ligament injuries (972) verified by arthroscopic evaluation at hospitals in the Hordaland region of Norway from 1982 to 1991. Our final study group comprised 176 patients who had participated in organized soccer and answered a questionnaire. The overall incidence rate was 0.063 injuries per 1000 game hours. Men incurred 75.6% (133) of the injuries. Women had an incidence rate of 0.10 injuries per 1000 game hours, significantly higher than that for men (0.057). The incidence rate was higher (0.41) for men in the top three divisions. Most of the injuries (124) occurred during games. Contact injuries from tackling was the injury mechanism in 46.0% of the cases. Players on the offensive team incurred 122 (69.3%) of the injuries. Reconstructive surgery was performed on 131 (74.4%) of the injured players and was found necessary for return to a high level of play. Half of the players (87) returned to soccer; men at high levels of play had the highest return rate (88.9%), and men over age 34 had the poorest return rate (22.9%). Nearly one-third of the injured athletes gave up soccer because of poor knee function or fear of new injury.

Gibberellin (GA) 20-oxidase catalyses consecutive steps late in GA biosynthesis in plants. In Arabidopsis, the enzyme is encoded by a gene family of at least three members (AtGA20ox1, AtGA20ox2 and AtGA20ox3) with differential patterns of expression. The genes are regulated by feedback from bioactive GAs, suggesting that the enzymes may be involved in regulating GA biosynthesis. To investigate this, we produced transgenic Arabidopsis expressing sense or antisense copies of each of the GA 20-oxidase cDNAs. Over-expression of any of the cDNAs gave rise to seedlings with elongated hypocotyls; the plants flowered earlier than controls in both long and short days and were 25% taller at maturity. GA analysis of the vegetative rosettes showed a two- to threefold increase in the level of GA4, indicating that GA 20-oxidase normally limits bioactive GA levels. Plants expressing antisense copies of AtGA20ox1 had short hypocotyls and reduced rates of stem elongation. This was reflected in reduced levels of GA4 in both rosettes and shoot tips. In short days, flowering was delayed and the reduction in the rate of stem elongation was greater. Antisense expression of AtGA20ox2 had no apparent effects in long days, but stem growth in one transgenic line grown in short days was reduced by 20%. Expression of antisense copies of AtGA20ox3 had no visible effect, except for one transgenic line that had short hypocotyls. These results demonstrate that GA levels and, hence, plant growth and development can be modified by manipulation of GA 20-oxidase expression in transgenic plants.