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1.
Sci Total Environ ; 650(Pt 2): 1759-1770, 2019 Feb 10.
Article in English | MEDLINE | ID: mdl-30278420

ABSTRACT

Pervious pavement systems can have a life span of about 20years but, at end-of-life, it becomes necessary to evaluate the state of the infrastructure to determine whether they pose a health and safety risk to workers during dismantling, and also determine potential reuse of the waste material generated. In this paper, we report of an investigation conducted to evaluate whether Pervious pavement systems are hazardous to human health at end-of-life and also to assess the mobility of the stormwater pollutants trapped in the system as a measure of their potential release to receiving systems such as water-bodies and groundwater systems. After decommissioning, the pervious pavement structure was sampled for analysis including Gas Chromatography, inductively coupled plasma spectroscopy and, leachate analysis. Results show that carcinogenic risks were significantly below the regulatory limit of 1×10-6 while, the hazard quotients and cumulative hazard indices were also below regulatory value of 1, based on United States Environmental Protection Agency standards. Furthermore, mean concentrations of benzene, toluene, ethylbenzene and xylene were significantly less than the UK soil guideline values. The results of the leachate analysis show that the metals of concern, Pb, Zn, Cr, Ni, Cd and Cu were all below the threshold for reuse applications such as irrigation purposes as they were all below the regulatory limits such as Food and Agriculture Organization and, United States Environmental Protection Agency standards. Finally, the evaluation of potential reuse and recycling purposes indicate that wastes generated from the dismantling of the PPS are within limits for recycling as aggregates for other civil engineering projects as per European Union standards. This has potential to enhance UK's drive to achieve the target of 70% level of construction & demolition waste recovery for reuse and recycling by the year 2020 as per European Union Water Framework Directive.


Subject(s)
Construction Materials/toxicity , Environmental Monitoring , Recycling , Soil Pollutants/analysis , Water Pollutants, Chemical/analysis , Humans , Rain , Risk Assessment , United Kingdom
2.
Can Commun Dis Rep ; 41(10): 223-226, 2015 Oct 01.
Article in English | MEDLINE | ID: mdl-29769916

ABSTRACT

WHAT IS ALREADY KNOWN ON THIS TOPIC?: Q fever is a zoonotic disease caused by Coxiella burnetii and is usually transmitted through inhalation of air contaminated with animal excreta. The disease is considered to be underdiagnosed because symptoms are nonspecific and can vary from patient to patient, making diagnosis difficult. WHAT IS ADDED BY THIS REPORT?: During September-October 2014, the New York State Department of Health identified Q fever in five patients with exposure to a treatment known as live cell therapy, an alternative medicine practice involving injections of fetal sheep cells, which is a type of xenotransplantation. Investigation revealed that a group of U.S. residents traveled to Germany twice a year to receive this treatment. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE?: Clinicians should consider zoonotic diseases, such as Q fever, in patients whose history includes receipt of a treatment known as live cell therapy. International travel for xenotransplantation procedures can facilitate transmission of zoonotic disease.

3.
J Contam Hydrol ; 126(1-2): 72-84, 2011 Sep 25.
Article in English | MEDLINE | ID: mdl-21871689

ABSTRACT

Cosolvent flushing is a technique that has been proposed for the removal of hydrophobic organic contaminants in the subsurface. Cosolvents have been shown to dramatically increase the solubility of such compounds compared to the aqueous solubility; however, limited data are available on the effectiveness of cosolvents for field-contaminated media. In this work, we examine cosolvent flushing for the removal of polycyclic aromatic hydrocarbons (PAHs) in soil from a former manufactured gas plant (FMGP). Batch studies confirmed that the relationship between the soil-cosolvent partitioning coefficient (K(i)) and the volume fraction of cosolvent (f(c)) followed a standard log-linear equation. Using methanol at an fc of 0.95, column studies were conducted at varying length scales, ranging from 11.9 to 110 cm. Removal of PAH compounds was determined as a function of pore volumes (PVs) of cosolvent flushed. Despite using a high f(c), rate and chromatographic effects were observed in all the columns. PAH effluent concentrations were modeled using a common two-site sorption model. Model fits were improved by using MeOH breakthrough curves to determine fitted dispersion coefficients. Fitted mass-transfer rates were two to three orders of magnitude lower than predicted values based on published data using artificially contaminated sands.


Subject(s)
Environmental Restoration and Remediation/methods , Methanol/chemistry , Polycyclic Aromatic Hydrocarbons/chemistry , Soil Pollutants/chemistry , Solvents/chemistry , Coal , Models, Theoretical , Petroleum , Polycyclic Aromatic Hydrocarbons/analysis , Porosity , Soil Pollutants/analysis
4.
Water Sci Technol ; 64(6): 1333-9, 2011.
Article in English | MEDLINE | ID: mdl-22214088

ABSTRACT

Geotextiles incorporating inorganic nutrients (particularly phosphorous) to enhance the growth of oil degrading microoganisms when geotextiles are used in pervious pavement applications have been shown to be effective in the past. However the cost and manufacturing difficulties have been a barrier to their use. A polypropylene random mat geotextile incorporating an alternative polymer additive as a source of phosphorus has been investigated as a potential self-fertilising geotextile. Experiments are reported which investigate nutrient leach rates, biofilm formation and biodegradation activity.


Subject(s)
Biodegradation, Environmental , Bacteria/growth & development , Bacteria/metabolism , Hydrocarbons/metabolism , Microscopy, Electron, Scanning
5.
Water Sci Technol ; 45(7): 51-6, 2002.
Article in English | MEDLINE | ID: mdl-11989892

ABSTRACT

This paper reports on continuing research at Coventry University into the improvement of highway water quality following flow through a permeable pavement. Such pavements have been shown elsewhere to be efficient in-situ bio-reactors, capable of degrading large quantities of clean motor oil. Further laboratory research, reported here, demonstrates that a commercially obtained oil degrading, microbial mixture was not significantly better at degrading clean motor oil than the indigenous microbial biomass established within the pavement over a 4-year period, when provided with an adequate nutrient supply. Scanning electron microscopy has been used to monitor biofilm development, which has also identified that the pavement has developed a complex community structure with high bio-diversity.


Subject(s)
Biofilms , Fuel Oils , Water Pollutants, Chemical/metabolism , Biodegradation, Environmental , Biomass , Microscopy, Electron, Scanning , Permeability
6.
Dev Biol ; 237(1): 173-82, 2001 Sep 01.
Article in English | MEDLINE | ID: mdl-11518514

ABSTRACT

During Caenorhabditis elegans hermaphrodite development, the anchor cell induces the vulva and the uterine pi cells whose daughters connect to the vulva, thereby organizing the uterine-vulval connection. Both the initial selection of a single anchor cell during the anchor cell vs. ventral uterine precursor cell decision and the subsequent induction of the pi cell fate by the anchor cell are mediated by the lin-12 gene. Members of the presenilin gene family can cause early onset Alzheimer's disease when mutated and are also required for LIN-12/Notch signaling during development. We have shown that, in C. elegans, mutation of the sel-12-encoded presenilin results in pi cell induction defects. By contrast, other lin-12-mediated cell fate decisions occur normally in sel-12 mutants due to the redundant function of a second C. elegans presenilin called HOP-1. We found that the sel-12 egg-laying defect was partially rescued by expression of the sel-12 gene in the pi cells. sel-12-mediated pi cell fate specification provides a useful system for the analysis of presenilin function at single cell resolution.


Subject(s)
Caenorhabditis elegans Proteins , Caenorhabditis elegans/physiology , Helminth Proteins/physiology , Membrane Proteins/physiology , Uterus/embryology , Animals , Female , Helminth Proteins/chemistry , Helminth Proteins/genetics , Membrane Proteins/chemistry , Membrane Proteins/genetics , Mutation , Oviposition , Uterus/cytology
7.
Br Dent J ; 190(10): 558-60, 2001 May 26.
Article in English | MEDLINE | ID: mdl-11411891

ABSTRACT

OBJECTIVE: To investigate the release of mercury vapour from a dental aspirator which vented its waste air through its base directly into the surgery environment. METHODOLOGY: Mercury vapour in air concentrations were measured at the breathing zone of the dentist during continuous operation of the aspirator. Further series of mercury vapour measurements taken at the aspirator exhaust vent were carried out to determine the sources of mercury vapour from this particular device. RESULTS: At the dentist's breathing zone, mercury vapour concentrations of ten times the current occupational exposure limit of 25 micrograms/m3 were recorded after 20 minutes of continuous aspirator operation. A build up of amalgam contamination within the internal corrugated tubing of the aspirator was found to be the main source of mercury vapour emissions followed by particulate amalgam trapped within the vacuum motor. As the vacuum motor heated up with run time, mercury vapour emissions increased. It was found that the bacterial air exhaust filter (designed to clean the contaminated waste air entering the surgery) offered no protection to mercury vapour. In this case the filter trapped particulate amalgam which contributed to further mercury vapour contamination as high volume air was vented through it. CONCLUSION: It is not known how many dental aspirators are in use that vent their waste air directly into the surgery or if this aspirator is representative of others in existence. The safety of dental aspirating systems with regard to mercury vapour exposure requires further investigation.


Subject(s)
Air Pollution, Indoor , Dental Equipment , Dentistry , Mercury/analysis , Occupational Exposure , Humans , Maximum Allowable Concentration , Spectrophotometry, Atomic , Vacuum , Volatilization
8.
Curr Biol ; 10(23): 1479-88, 2000 Nov 30.
Article in English | MEDLINE | ID: mdl-11114514

ABSTRACT

BACKGROUND: The development of a connection between the uterus and the vulva in the nematode Caenorhabditis elegans requires specification of a uterine cell called the utse, and its attachment to the vulva and the epidermal seam cells. The uterine pi cells generate the utse and uv1 cells, which also connect the uterus to the vulva. The uterine anchor cell (AC) induces the vulva through LIN-3/epidermal growth factor (EGF) signaling, and the pi cells through LIN-12/Notch signaling. Here, we report that a gene required for seam cell maturation is also required for specification of the utse and for vulval differentiation, and thus helps to coordinate development of the vulval-uterine-seam cell connection. RESULTS: We cloned the egl-29 gene, which is necessary for induction of uterine pi cells, and found it to be allelic to lin-29, which encodes a zinc finger transcription factor that is necessary for the terminal differentiation of epidermal seam cells. In the uterus, lin-29 functioned upstream of lin-12 in the induction of pi cells and was necessary to maintain expression in the AC of lag-2, which encodes a ligand for LIN-12. CONCLUSIONS: The lin-29 gene controls gene expression in the epidermal seam cells, uterus and vulva, and may help to coordinate the terminal development of these three tissues by regulating the timing of late gene expression during organogenesis.


Subject(s)
Caenorhabditis elegans Proteins , Caenorhabditis elegans/genetics , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Developmental , Transcription Factors/genetics , Transcription Factors/metabolism , Amino Acid Sequence , Animals , Base Sequence , Caenorhabditis elegans/growth & development , Cell Differentiation , Cell Fusion , DNA-Binding Proteins/chemistry , Epidermal Cells , Epidermis/metabolism , Female , Helminth Proteins/genetics , Helminth Proteins/metabolism , Molecular Sequence Data , Mutation , Transcription Factors/chemistry , Uterus/abnormalities , Uterus/cytology , Uterus/growth & development , Uterus/metabolism , Vulva/abnormalities , Vulva/cytology , Vulva/growth & development , Vulva/metabolism
9.
Development ; 126(23): 5319-26, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10556057

ABSTRACT

The Caenorhabditis elegans hermaphrodite egg-laying system comprises several tissues, including the uterus and vulva. lin-11 encodes a LIM domain transcription factor needed for certain vulval precursor cells to divide asymmetrically. Based on lin-11 expression studies and the lin-11 mutant phenotype, we find that lin-11 is also required for C. elegans uterine morphogenesis. Specifically, lin-11 is expressed in the ventral uterine intermediate precursor (pi) cells and their progeny (the utse and uv1 cells), which connect the uterus to the vulva. Like (pi) cell induction, the uterine lin-11 expression responds to the uterine anchor cell and the lin-12-encoded receptor. In wild type animals, the utse, which forms the planar process at the uterine-vulval interface, fuses with the anchor cell. We found that, in lin-11 mutants, utse differentiation was abnormal, the utse failed to fuse with the anchor cell and a functional uterine-vulval connection was not made. These findings indicate that lin-11 is essential for uterine-vulval morphogenesis.


Subject(s)
Caenorhabditis elegans Proteins , Caenorhabditis elegans/physiology , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Uterus/embryology , Amino Acid Motifs , Animals , Cadherins/genetics , Cadherins/metabolism , Cell Lineage , Cell Movement/genetics , Embryo, Nonmammalian , Embryonic Induction/genetics , Female , Gene Expression Regulation, Developmental , Helminth Proteins/genetics , Helminth Proteins/metabolism , Membrane Proteins/genetics , Membrane Proteins/metabolism , Morphogenesis , Mutation , Receptors, Notch , Transcription Factors/genetics , Transcription Factors/metabolism , Uterus/cytology , Uterus/physiology , Vulva/embryology , Vulva/physiology , Vulva/ultrastructure , beta-Galactosidase/genetics , beta-Galactosidase/metabolism
10.
Curr Biol ; 9(5): 237-46, 1999 Mar 11.
Article in English | MEDLINE | ID: mdl-10074449

ABSTRACT

BACKGROUND: Reciprocal signaling between distinct tissues is a general feature of organogenesis. Despite the identification of developmental processes in which coordination requires reciprocal signaling, little is known regarding the underlying molecular details. Here, we use the development of the uterine-vulval connection in the nematode Caenorhabditis elegans as a model system to study reciprocal signaling. RESULTS: In C. elegans, development of the uterine-vulval connection requires the specification of uterine uv1 cells and morphogenesis of 1 degrees -derived vulval cells. LIN-3, an epidermal growth factor (EGF) family protein, is first produced by the gonadal anchor cell to induce vulval precursor cells to generate vulval tissue. We have shown that lin-3 is also expressed in the 1 degrees vulval lineage after vulval induction and that the 1 degrees vulva is necessary to induce the uv1 uterine cell fate. Using genetic and cell biological analyses, we found that the specification of uterine uv1 cells is dependent on EGF signaling from cells of the 1 degrees vulval lineages to a subset of ventral uterine cells of the gonad. RAS and RAF are necessary for this signaling. We also found that EGL-38, a member of the PAX family of proteins, is necessary for transcription of lin-3 in the vulva but not in the anchor cell. A let-23 mutation that confers ligand-independent activity bypasses the requirement for EGL-38 in specification of the uv1 cell fate. CONCLUSIONS: We have shown how relatively simple EGF signals can be used reciprocally to specify the uterine-vulval connection during C. elegans development.


Subject(s)
Caenorhabditis elegans Proteins , Epidermal Growth Factor/metabolism , Helminth Proteins/metabolism , Signal Transduction , Animals , Caenorhabditis elegans/genetics , Caenorhabditis elegans/metabolism , Cell Lineage , Epidermal Growth Factor/genetics , Epithelium , ErbB Receptors/genetics , ErbB Receptors/metabolism , Female , Gene Expression , Helminth Proteins/genetics , Morphogenesis , Uterus/metabolism , Uterus/physiology , Vulva/metabolism , Vulva/physiology , ras Proteins/genetics , ras Proteins/metabolism
11.
Am J Sports Med ; 26(2): 309-24, 1998.
Article in English | MEDLINE | ID: mdl-9548130

ABSTRACT

Articular cartilage can tolerate a tremendous amount of intensive and repetitive physical stress. However, it manifests a striking inability to heal even the most minor injury. Both the remarkable functional characteristics and the healing limitations reflect the intricacies of its structure and biology. Cartilage is composed of chondrocytes embedded within an extracellular matrix of collagens, proteoglycans, and noncollagenous proteins. Together, these substances maintain the proper amount of water within the matrix, which confers its unique mechanical properties. The structure and composition of articular cartilage varies three-dimensionally, according to its distance from the surface and in relation to the distance from the cells. The stringent structural and biological requirements imply that any tissue capable of successful repair or replacement of damaged articular cartilage should be similarly constituted. The response of cartilage to injury differs from that of other tissues because of its avascularity, the immobility of chondrocytes, and the limited ability of mature chondrocytes to proliferate and alter their synthetic patterns. Therapeutic efforts have focused on bringing in new cells capable of chondrogenesis, and facilitating access to the vascular system. This review presents the basic science background and clinical experience with many of these methods and information on synthetic implants and biological adhesives. Although there are many exciting avenues of study that warrant enthusiasm, many questions remain. These issues need to be addressed by careful basic science investigations and both short- and long-term clinical trials using controlled, prospective, randomized study design.


Subject(s)
Cartilage, Articular/injuries , Cartilage, Articular/surgery , Cartilage, Articular/anatomy & histology , Cartilage, Articular/physiopathology , Humans , Tissue Transplantation , Wound Healing
12.
Development ; 124(20): 3919-28, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9374390

ABSTRACT

Mutations in the C. elegans gene egl-38 result in a discrete set of defects in developmental pattern formation. In the developing egg-laying system of egl-38 mutant hermaphrodites, the identity of four uterine cells is disrupted and they adopt the fate of their neighbor cells. Likewise, the identity of two rectal epithelial cells in the male tail is disrupted and one of these cells adopts the fate of its neighbor cell. Genetic analysis suggests that the egl-38 functions in the tail and the egg-laying system are partially separable, as different egl-38 mutations can preferentially disrupt the different functions. We have cloned egl-38 and shown that it is a member of the PAX family of genes, which encode transcription factors implicated in a variety of developmental patterning events. The predicted EGL-38 protein is most similar to the mammalian class of proteins that includes PAX2, PAX5 and PAX8. The sequence of egl-38 mutant DNA indicates that the tissue-preferential defects of egl-38 mutations result from substitutions in the DNA-binding paired domain of the EGL-38 protein. egl-38 thus provides the first molecular genetic insight into two specific patterning events that occur during C. elegans development and also provides the opportunity to investigate the in vivo functions of this class of PAX proteins with single cell resolution.


Subject(s)
Caenorhabditis elegans/embryology , Caenorhabditis elegans/genetics , DNA-Binding Proteins/genetics , Gene Expression Regulation, Developmental , Nuclear Proteins/genetics , Trans-Activators/genetics , Transcription Factors/genetics , Amino Acid Sequence , Animals , Base Sequence , Male , Molecular Sequence Data , PAX2 Transcription Factor , PAX5 Transcription Factor , Sequence Alignment
13.
Ultrason Sonochem ; 4(2): 153-6, 1997 Apr.
Article in English | MEDLINE | ID: mdl-11237034

ABSTRACT

Granular pieces of brick impregnated with copper oxide were used as a model for contaminated soil. Washing this model substrate by passing water across the substrate on an ultrasonically shaken tray irradiation afforded a 40% reduction in copper content. This was compared with only a 6% reduction when the sample was treated under otherwise identical conditions but using a tray shaken conventionally. The majority of the copper was removed as a result of the removal of surface materials which were more heavily contaminated with the copper oxide.


Subject(s)
Copper/isolation & purification , Environmental Pollution , Refuse Disposal/methods , Soil Pollutants/isolation & purification , Ultrasonics
14.
Ultrason Sonochem ; 4(2): 157-64, 1997 Apr.
Article in English | MEDLINE | ID: mdl-11237035

ABSTRACT

The effect of ultrasound upon the destruction of micro-organisms has been studied and reported here. The results obtained from the work carried out has shown that ultrasound can be used effectively for water disinfection and has several advantages. When used in conjunction with chlorine it significantly reduces the number of bacteria present in water samples. Ultrasound also reduces the amount of chlorine required for disinfection. Increasing the power of ultrasound leads to greater efficiency in the destruction of bacterial cells. High frequency ultrasound is more beneficial than low frequency in the disinfection of water.


Subject(s)
Chlorine , Ultrasonics , Water Microbiology , Water Purification/methods , Water/parasitology , Communicable Disease Control , Disinfection/methods , Humans
15.
Development ; 122(11): 3617-26, 1996 Nov.
Article in English | MEDLINE | ID: mdl-8951077

ABSTRACT

We have undertaken electron micrographic reconstruction of the Caenorhabditis elegans hermaphrodite uterus and determined the correspondence between cells defined by their lineage history and differentiated cell types. In this organ, many cells do not move during morphogenesis and the cell lineage may function to put cells where they are needed. Differentiated uterine cell types include the toroidal ut cells that make structural epithelium, and specialized utse and uv cells that make the connection between the uterus and the vulva. A cell fate decision in which the anchor cell (AC) induces adjacent ventral uterine intermediate precursor cells to adopt the pi fate, rather than the ground state rho, has profound consequences for terminal differentiation: all pi progeny are directly involved in making the uterine-vulval connection whereas all rho progeny contribute to ut toroids or the uterine-spermathecal valve. In addition to specifying certain uterine cell fates, the AC also induces the vulva. Its multiple inductions thereby function to coordinate the connection of an internal to an external epithelium. The AC induces the pi cells and ultimately fuses with a subset of their progeny. This is an example of reciprocal cell-cell interaction that can be studied at single cell resolution. The AC is thus a transitory cell type that plays a pivotal role in organizing the morphogenesis of the uterine-vulval connection.


Subject(s)
Caenorhabditis elegans/embryology , Animals , Caenorhabditis elegans/cytology , Cell Adhesion , Embryonic Induction , Epithelial Cells , Female , Gene Expression Regulation, Developmental , Morphogenesis , Uterus/cytology , Uterus/embryology , Vulva/cytology
16.
Proc Natl Acad Sci U S A ; 93(18): 9329-33, 1996 Sep 03.
Article in English | MEDLINE | ID: mdl-8790329

ABSTRACT

Development of the nematode egg-laying system requires the formation of a connection between the uterine lumen and the developing vulval lumen, thus allowing a passage for eggs and sperm. This relatively simple process serves as a model for certain aspects of organogenesis. Such a connection demands that cells in both tissues become specialized to participate in the connection, and that the specialized cells are brought in register. A single cell, the anchor cell, acts to induce and to organize specialization of the epidermal and uterine epithelia, and registrates these tissues. The inductions act via evolutionarily conserved intercellular signaling pathways. The anchor cell induces the vulva from ventral epithelial cells via the LIN-3 growth factor and LET-23 transmembrane tyrosine kinase. It then induces surrounding uterine intermediate precursors via the receptor LIN-12, a founding member of the Notch family of receptors. Both signaling pathways are used multiple times during development of Caenorhabditis elegans. The outcome of the signaling is context-dependent. Both inductions are reciprocated. After the anchor cell has induced the vulva, it stretches toward the induced vulval cells. After the anchor cell has induced specialized uterine intermediate precursor cells, it fuses with a subset of their progeny.


Subject(s)
Caenorhabditis elegans Proteins , Caenorhabditis elegans/genetics , Gene Expression Regulation, Developmental , Uterus/embryology , Vulva/embryology , Animals , Caenorhabditis elegans/embryology , Cell Communication , Cell Differentiation , Cell Fusion , Epidermal Growth Factor/metabolism , Epithelium/embryology , ErbB Receptors/metabolism , Female , Helminth Proteins/metabolism , Morphogenesis/genetics
17.
Arthroscopy ; 12(4): 414-21, 1996 Aug.
Article in English | MEDLINE | ID: mdl-8863998

ABSTRACT

Seventy-eight of 113 consecutive patellar tendon anterior cruciate ligament reconstructions (autograft, 47 of 66; allograft, 31 of 47) were evaluated at an average of 34 months. Reconstructions were compared with Lysholm and Tegner knee-rating scales, physical examination findings, instrumented laxity values, single-leg hop distances, and isokinetic strength results. Lysholm scores > or = 90 were achieved by 69% of autograft patients versus 67% of allograft patients. Desired Tegner activity scores were achieved by 80% of autograft patients versus 74% of allograft patients. Patellofemoral signs and symptoms were absent in 40% of autograft patients versus 44% of allograft patients. Side-to-side laxity differences < or = 3 mm were achieved in 80% of autograft patients versus 70% of allograft patients. Single-leg hop scores > or = 90% of the nonoperated leg were obtained in 76% of autograft patients versus 81% of allograft patients. Isokinetic results between groups were also similar. Traumatic ruptures were sustained by four allograft patients at an average of 11 months postoperatively compared with no traumatic ruptures in the autograft group (P = .011). This was the only difference of statistical significance.


Subject(s)
Anterior Cruciate Ligament Injuries , Anterior Cruciate Ligament/surgery , Knee Injuries/surgery , Tendons/transplantation , Adult , Female , Follow-Up Studies , Humans , Joint Instability/epidemiology , Knee Injuries/physiopathology , Knee Joint/physiopathology , Male , Postoperative Complications/epidemiology , Retrospective Studies , Rupture , Tendon Injuries/epidemiology , Time Factors , Transplantation, Autologous , Transplantation, Homologous , Treatment Outcome
18.
Development ; 121(2): 263-71, 1995 Feb.
Article in English | MEDLINE | ID: mdl-7768171

ABSTRACT

The anchor cell (AC) of the Caenorhabditis elegans gonad has a critical role in the development of a functional egg-laying system, which is accomplished through cell-cell interactions. Lateral inhibitory lin-12-mediated signaling among two bipotential cells causes one to adopt the ventral uterine precursor (VU) cell fate while the other becomes the AC. The AC then induces formation of vulval tissue. We find that the AC also induces a particular ventral uterine intermediate precursor fate (pi) by a mechanism that is genetically and temporally distinct from vulval induction. This process requires lin-12, but unlike previously described lin-12-mediated decisions, signaling is unidirectional, is between dissimilar cells and does not involve lateral inhibition. The pi fates are necessary for egg laying and appear to produce a distinct specialized cell type. Thus, patterning of the ventral uterus by the AC is crucial to the development of a functional egg-laying system.


Subject(s)
Caenorhabditis elegans/embryology , Embryonic Induction/genetics , Genes, Helminth , Germ Cells/cytology , Oviposition , Uterus/embryology , Animals , Caenorhabditis elegans/genetics , Female , Microscopy, Electron , Morphogenesis/genetics , Vulva/embryology
19.
J Trauma ; 34(3): 383-9, 1993 Mar.
Article in English | MEDLINE | ID: mdl-8483179

ABSTRACT

Complete dislocation of the knee is recognized to be an extremely severe injury, representing one of the few true orthopedic emergencies. There is major trauma to the ligaments, capsule, and tendons, with a high incidence of associated damage to the popliteal artery and peroneal nerve. Resulting disability can be great, reflected by pain, stiffness, or instability of the knee; neurologic deficits in the foot and ankle; and even amputation if the vascular injury is not addressed promptly. Most accounts of knee dislocations in the literature have suggested that disruption of both cruciate ligaments is necessary for a complete dislocation to occur. This consensus is based on clinical observations and some laboratory investigations of ligament failure patterns. This report presents four cases of complete tibiofemoral knee dislocation without disruption of both cruciate ligaments. We also review the literature on knee dislocations with an emphasis on the biomechanics of soft tissue restraints about the knee and analyze how sufficient laxity can occur, with one cruciate ligament remaining intact, to allow for complete knee dislocation.


Subject(s)
Joint Dislocations , Knee Injuries , Ligaments, Articular , Adolescent , Adult , Biomechanical Phenomena , Female , Humans , Joint Dislocations/physiopathology , Knee Injuries/physiopathology , Ligaments, Articular/physiopathology , Male , Middle Aged , Time Factors
20.
Am J Sports Med ; 21(2): 271-6, 1993.
Article in English | MEDLINE | ID: mdl-8465924

ABSTRACT

A 5-year prospective study on the time course of women's gymnastics injuries was conducted on a successful NCAA Division I team. Gymnasts recorded injuries on a computer terminal or via computer dot sheets immediately before each training session, including the injured body part, the event or activity, and the date of the injury. The definition of injury was "any damaged body part that would interfere with training." Athletes recorded injuries on the 1st day of onset and subsequently until the injury was healed. The initial onset of injury was considered a new injury. Subsequent records of the injury were considered continuing injury. Thirty-seven athletes participated through five collegiate seasons. They accounted for 5602 total training exposures with an average of 151.4 exposures per athlete. The analyses showed that gymnasts trained with an injury approximately 71% of the exposures, and a new injury could be expected from a gymnast during approximately 9% of the exposures. The largest number of injuries were of the repetitive stress syndrome type. The time series information showed that total injuries tended to increase until the middle of the competitive season, while new injuries showed prominent increases during specific training periods and during competition preparation and performance.


Subject(s)
Gymnastics/injuries , Adult , Athletic Injuries/epidemiology , Cumulative Trauma Disorders/epidemiology , Female , Humans , Physical Education and Training , Prospective Studies , Utah/epidemiology
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