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1.
Int J Law Psychiatry ; 83: 101810, 2022.
Article in English | MEDLINE | ID: mdl-35696760

ABSTRACT

Studies seeking predictors of outcomes after involuntary admission, including quality of life (QoL), are limited and results inconsistent. We aimed to describe QoL 3 months after involuntary psychiatric admission and to investigate associated factors. One hundred and fifty-three involuntarily admitted inpatients were assessed for a range of sociodemographic and clinical variables. Structured scales included the Brief Psychiatric Rating Scale (BPRS), the MacArthur Admission Experience Survey, the Heinrichs Quality of Life Scale and the World Health Organisation Quality of Life Brief Assessment (WHOQOL-BREF, n = 124). The mean total score on the Heinrichs QoL scale at 3 months was 69.3 (SD = 24.1). Predictors of higher 3 month QoL after involuntary admission in a multiple regression model (adjusted R2 = 0.37, F = 7.1 (14, 138), p ≤0.001) were less severe negative symptoms on the BPRS at baseline (B = -4.56, p < 0.001), improvement in negative symptom scores between baseline and follow up (B = 4.58, p < 0.001) and higher current social class (B = -14.31, p = 0.001). Events during involuntary admission, such as being subject to coercive experiences, were not significantly associated with QoL after admission. The results suggest that a core determinant of service users' QoL after involuntary admission is negative symptom severity and change over time.


Subject(s)
Coercion , Quality of Life , Hospitalization , Humans , Inpatients/psychology , Surveys and Questionnaires
2.
Comput Methods Biomech Biomed Engin ; 24(12): 1310-1325, 2021 Sep.
Article in English | MEDLINE | ID: mdl-33641546

ABSTRACT

Musculoskeletal models of the lumbar spine have been developed with varying levels of detail for a wide range of clinical applications. Providing consistency is ensured throughout the modelling approach, these models can be combined with other computational models and be used in predictive modelling studies to investigate bone health deterioration and the associated fracture risk. To provide precise physiological loading conditions for such predictive modelling studies, a new full-body musculoskeletal model including a detailed and consistent representation of the lower limbs and the lumbar spine was developed. The model was assessed against in vivo measurements from the literature for a range of spine movements representative of daily living activities. Comparison between model estimations and electromyography recordings was also made for a range of lifting tasks. This new musculoskeletal model will provide a comprehensive physiological mechanical environment for future predictive finite element modelling studies on bone structural adaptation. It is freely available on https://simtk.org/projects/llsm/.


Subject(s)
Lumbar Vertebrae , Lumbosacral Region , Biomechanical Phenomena , Electromyography , Lower Extremity , Weight-Bearing
3.
Ir J Psychol Med ; 35(2): 87, 2018 06.
Article in English | MEDLINE | ID: mdl-30115200
4.
Med Phys ; 42(12): 7078-89, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26632061

ABSTRACT

PURPOSE: Focal therapy has been proposed as an alternative method to whole-gland treatment for prostate cancer when aiming to reduce treatment side effects. The authors recently validated a radiobiological model which takes into account tumor location and tumor characteristics including tumor cell density, Gleason score, and hypoxia in order to plan optimal dose distributions for focal therapy. The authors propose that this model can be informed using multiparametric MRI (mpMRI) and in this study present a registration framework developed to map prostate mpMRI and histology data, where histology will provide the "ground truth" data regarding tumor location and biology. The authors aim to apply this framework to a growing database to develop a prostate biological atlas which will enable MRI based planning for prostate focal therapy treatment. METHODS: Six patients scheduled for routine radical prostatectomy were used in this proof-of-concept study. Each patient underwent mpMRI scanning prior to surgery, after which the excised prostate specimen was formalin fixed and mounted in agarose gel in a custom designed sectioning box. T2-weighted MRI of the specimen in the sectioning box was acquired, after which 5 mm sections of the prostate were cut and histology sections were microtomed. A number of image processing and registration steps were used to register histology images with ex vivo MRI and deformable image registration (DIR) was applied to 3D T2w images to align the in vivo and ex vivo MRI data. Dice coefficient metrics and corresponding feature points from two independent annotators were selected in order to assess the DIR accuracy. RESULTS: Images from all six patients were registered, providing histology and in vivo MRI in the ex vivo MRI frame of reference for each patient. Results demonstrated that their DIR methodology to register in vivo and ex vivo 3D T2w MRI improved accuracy in comparison with an initial manual alignment for prostates containing features which were readily visible on MRI. The average estimated uncertainty between in vivo MRI and histology was 3.3 mm, which included an average error of 3.1 mm between in vivo and ex vivo MRI after applying DIR. The mean dice coefficient for the prostate contour between in vivo and ex vivo MRI increased from 0.83 before DIR to 0.93 after DIR. CONCLUSIONS: The authors have developed a registration framework for mapping in vivo MRI data of the prostate with histology by implementing a number of processing steps and ex vivo MRI of the prostate specimen. Validation of DIR was challenging, particularly in prostates with few or mostly linear rather than spherical shaped features. Refinement of their MR imaging protocols to improve the data quality is currently underway which may improve registration accuracy. Additional mpMRI sequences will be registered within this framework to quantify prostate tumor location and biology.


Subject(s)
Histological Techniques/methods , Magnetic Resonance Imaging/methods , Prostate/pathology , Prostate/surgery , Prostatic Neoplasms/pathology , Prostatic Neoplasms/surgery , Aged , Atlases as Topic , Cell Count , Fixatives , Formaldehyde , Gels , Humans , Imaging, Three-Dimensional , Male , Microtomy , Middle Aged , Prostatectomy , Sepharose
5.
Ir J Psychol Med ; 31(3): 191-193, 2014 Sep.
Article in English | MEDLINE | ID: mdl-30189491

ABSTRACT

BACKGROUND: Co-prescription of linezolid and serotonergic agents (SSRIs, SNRIs, NaSSA, TCAs) can lead to serotonin syndrome, this study seeks to identify prescribing practise of these agents. METHODS: Study of all general hospital inpatients prescribed intravenous linezolid in a 3-month period, using drug charts and clinical notes. RESULTS: Co-prescription occurred in 20% with SSRIs most frequently concurrently used. There were no cases of serotonin syndrome. There was no evidence in clinical notes of vigilance for potential interaction. CONCLUSION: Co-prescription is common; awareness of potentially serious interaction is not evident in current practice.

6.
Theriogenology ; 78(2): 285-96, 2012 Jul 15.
Article in English | MEDLINE | ID: mdl-22578614

ABSTRACT

Evaluating ovarian cycle activity through longitudinal progestagen monitoring is important for optimizing breeding management of captive elephants and understanding impact of life events (births, deaths, and transfers) on reproductive function. This study summarized serum progestagen profiles for eight Asian mainland elephants (Elephas maximus indicus) and one Bornean elephant (E. maximus borneensis) at the Oregon Zoo over a 20-yr interval, and represents the longest longitudinal dataset evaluated to date. Estrous cycle characteristics were more varied than previously reported for this species, with an overall duration of 12 to 19 wk, luteal phase duration of 4 to 15 wk, and follicular phase duration of 2 to 12 wk. In general, there was more cycle variability across than within individual elephants. Compared with other elephants in the group, the Borneo female exhibited consistently longer cycle lengths, higher progestagen concentrations, and greater cycle variability; however, it is not known if this represents a subspecies or an individual difference. Cycle durations did not appear to change over time or with age, and the first pubertal cycle was similar to subsequent cycles. Variability in duration of the follicular phase was greater than that of the luteal phase. In addition, there was a significant negative relationship between luteal and follicular phase durations, suggesting a possible regulatory role of the follicular phase in maintaining a relatively consistent cycle duration within individuals. Overall, we found these elephants to be highly resilient in that major life events (births, deaths, and changes in herd structure) had minimal effect on cycle dynamics over time. In conclusion, the higher range in cycle phase characteristics is likely because of the larger number of elephants studied and longer duration of longitudinal monitoring, and may be more representative of the captive population as a whole. Furthermore, identification of significant interanimal variability suggests that understanding the complexities of herd reproductive characteristics could facilitate development of more effective institution-specific breeding management strategies.


Subject(s)
Animals, Zoo , Elephants/physiology , Estrous Cycle/physiology , Aging , Animals , Female , Longitudinal Studies , Oregon , Pregnancy , Progestins/blood , Progestins/metabolism , Radioimmunoassay , Time Factors
7.
Mol Oral Microbiol ; 25(6): 384-90, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21040512

ABSTRACT

Elevated proportions of Candida albicans in biofilms formed on dentures are associated with stomatitis whereas Streptococcus mutans accumulation on restorative materials can cause secondary caries. Candida albicans, S. mutans, saliva-derived and C. albicans/saliva-derived mixed biofilms were grown on different materials including acrylic denture, porcelain, hydroxyapatite (HA), and polystyrene. The resulting biomass was analysed by three-dimensional image quantification and assessment of colony-forming units. The efficacy of biofilm treatment with a dissolved denture cleansing tablet (Polident(®)) was also evaluated by colony counting. Biofilms formed on HA exhibited the most striking differences in biomass accumulation: biofilms comprising salivary bacteria accrued the highest total biomass whereas C. albicans biofilm formation was greatly reduced on the HA surface compared with other materials, including the acrylic denture surface. These results substantiate clinical findings that acrylic dentures can comprise a reservoir for C. albicans, which renders patients more susceptible to C. albicans infections and stomatitis. Additionally, treatment efficacy of the same type of biofilms varied significantly depending on the surface. Although single-species biofilms formed on polystyrene surfaces exhibited the highest susceptibility to the treatment, the most surviving cells were recovered from HA surfaces for all types of biofilms tested. This study demonstrates that the nature of a surface influences biofilm characteristics including biomass accumulation and susceptibility to antimicrobial treatments. Such treatments should therefore be evaluated on the surfaces colonized by the target pathogen(s).


Subject(s)
Anti-Infective Agents/pharmacology , Biofilms/growth & development , Dental Materials/chemistry , Acrylic Resins/chemistry , Bacterial Adhesion/drug effects , Bacterial Load , Biofilms/drug effects , Biomass , Borates/pharmacology , Candida albicans/drug effects , Candida albicans/physiology , Dental Plaque/microbiology , Dental Porcelain/chemistry , Denture Bases/microbiology , Denture Cleansers/pharmacology , Dentures , Durapatite/chemistry , Humans , Imaging, Three-Dimensional , Materials Testing , Microbial Sensitivity Tests , Microscopy, Confocal , Polystyrenes/chemistry , Saliva/microbiology , Streptococcus mutans/drug effects , Streptococcus mutans/physiology , Sulfates/pharmacology , Surface Properties
8.
Theriogenology ; 74(9): 1701-6, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20615535

ABSTRACT

The objective was to determine if seminal alkaline phosphatase (ALP) can serve as an indicator of true ejaculation in the rhinoceros. Concentrations of ALP activity were determined in seminal fractions collected from African black rhinos (Diceros bicornis), an African white rhino (Ceratotherium simum), and an Indian rhino (Rhinoceros unicornis) during electroejaculation. In addition, seminal fractions collected during penile massage of a Sumatran rhino (Dicerorhinus sumatrensis) were assessed. Correlations between ALP activity and sperm concentration, fraction pH, and fraction osmolality were evaluated in the Indian rhino and black rhino. Concentrations of ALP activity in rhino ejaculate fractions ranged from < 5 to 11,780 U/L and were positively correlated (P < 0.05) with sperm concentration for both Indian rhino (r = 0.995) and black rhino (r = 0.697), but did not exhibit a strong correlation with either pH or osmolality (P > 0.05). Data were insufficient for establishing meaningful correlation coefficients in the Sumatran rhino and white rhino, but preliminary results were in accordance with findings in the Indian rhino and black rhino. We concluded that ALP was present in rhinoceros semen, likely originated from the epididymides and/or testes, and could serve as a useful tool for assessing the production of ejaculatory versus pre-ejaculatory fluid in the rhinoceros.


Subject(s)
Alkaline Phosphatase/analysis , Ejaculation , Perissodactyla/metabolism , Semen/enzymology , Animals , Hydrogen-Ion Concentration , Male , Osmolar Concentration , Sperm Count/veterinary
9.
Exp Oncol ; 31(3): 185-7, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19783960

ABSTRACT

AIM: Recent literature suggests that some human cancer cell lines possess a calcium cation receptor. Human myeloma cell lines have demonstrated stimulated cell proliferation by the gadolinium cation through this receptor, and osteosarcoma cell lines possess the same cation receptor. Although enhanced MRI is a very useful diagnostic tool for the treatment of sarcoma in the orthopedic area, incorporating the use of MRI contrast agents based on gadolinium raises the possibility of the stimulation of cancer cell growth. METHODS: Human myeloma (RPMI 8226), osteosarcoma (Saos-2) and rat osteosarcoma (UMR-106) cell lines were exposed to various concentrations of common MRI contrast agent gadodiamide Omniscan (5 microM, 50 microM, 500 microM, 5 mM, 50 mM) in a culture medium. The response of the cells was then assessed by measuring cell proliferation and DNA synthesis. RESULTS: Treatment with 5 microM to 5 mM gadodiamide did not stimulate cell proliferation; only cells exposed to 50 mM gadodiamide showed suppressed proliferation rates. CONCLUSIONS: Since intravenously injected gadodiamide is diluted from 500 microM to 1 mM by patient blood flow at enhanced MRI examinations, the results of the present study suggest that gadodiamide has not effect on these types of cancer cells.


Subject(s)
Bone Neoplasms/drug therapy , Cell Proliferation/drug effects , Contrast Media/pharmacology , Gadolinium DTPA/pharmacology , Multiple Myeloma/drug therapy , Osteosarcoma/drug therapy , Animals , Bone Neoplasms/pathology , Cell Line, Tumor , DNA, Neoplasm/metabolism , Humans , Multiple Myeloma/pathology , Osteosarcoma/pathology , Rats
10.
Ecotoxicology ; 18(2): 250-8, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19015980

ABSTRACT

Toxicity effects of the antifouling compound, Irgarol 1051, were examined using a simulated estuarine salt marsh ecosystem. The 35 day mesocosm exposure incorporated tidal flux and contained seawater, sediments, marsh grass, and estuarine biota. Irgarol (10.0 microg/l) caused a significant reduction in phytoplankton biomass and primary productivity. HPLC pigment analysis indicated significant effects of irgarol on both phytoplankton and periphyton community composition, with decreased concentrations of pigments representative of diatom species. There was also a significant decrease in dissolved oxygen levels in the 10.0 microg/l irgarol treatment. Growth of the hard shell clam was significantly reduced in the 1.0 and 10.0 microg/l irgarol treatments. The effects observed occurred at irgarol concentrations greater than those typically measured in the environment. Prolonged exposure, the accumulation of irgarol in sediments, plant, or animal tissues, and the interaction of irgarol with other chemicals in the environment; however, could increase risk.


Subject(s)
Bivalvia/drug effects , Pesticides/toxicity , Photosynthesis/drug effects , Phytoplankton/drug effects , Poaceae/drug effects , Triazines/toxicity , Wetlands , Animals , Biomass , Bivalvia/growth & development , Chromatography, High Pressure Liquid , Oxygen/metabolism , Phytoplankton/growth & development , Population Dynamics
11.
Environ Toxicol ; 23(2): 224-32, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18214910

ABSTRACT

Triclosan, a commonly used antimicrobial compound, has been measured in aquatic systems worldwide. This study exposed marine species to triclosan to examine effects primarily on survival and to investigate the formation of the degradation product, methyl-triclosan, in the estuarine environment. Acute toxicity was assessed using the bacterium Vibrio fischeri, the phytoplankton species Dunaliella tertiolecta, and three life stages of the grass shrimp Palaemonetes pugio. P. pugio larvae were more sensitive to triclosan than adult shrimp or embryos. Acute aqueous toxicity values (96 h LC50) were 305 microg/L for adult shrimp, 154 microg/L for larvae, and 651 microg/L for embryos. The presence of sediment decreased triclosan toxicity in adult shrimp (24 h LC50s were 620 microg/L with sediment, and 482 microg/L without sediment). The bacterium was more sensitive to triclosan than the grass shrimp, with a 15 min aqueous IC50 value of 53 microg/L and a 15 min spiked sediment IC50 value of 616 microg/kg. The phytoplankton species was the most sensitive species tested, with a 96 h EC50 value of 3.55 microg/L. Adult grass shrimp were found to accumulate methyl-triclosan after a 14-day exposure to 100 microg/L triclosan, indicating formation of this metabolite in a seawater environment and its potential to bioaccumulate in higher organisms. Triclosan was detected in limited surface water sampling of Charleston Harbor, SC at a maximum concentration of 0.001 microg/L, substantially lower than the determined toxicity values. These findings suggest triclosan poses low acute toxicity risk to estuarine organisms; however, the potential for chronic, sublethal, and metabolite effects should be investigated.


Subject(s)
Anti-Infective Agents/toxicity , Triclosan/analogs & derivatives , Water Pollutants, Chemical/toxicity , Aliivibrio fischeri/drug effects , Animals , Anti-Infective Agents/analysis , Anti-Infective Agents/metabolism , Environmental Monitoring , Lethal Dose 50 , Palaemonidae/drug effects , Phytoplankton/drug effects , South Carolina , Triclosan/analysis , Triclosan/metabolism , Triclosan/toxicity , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/metabolism
13.
J Magn Reson Imaging ; 14(3): 203-6, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11536395

ABSTRACT

The purpose of this study was to determine whether oblique sagittal T2-weighted images of the anterior cruciate ligament (ACL) are better prescribed off axial or coronal localizing images. Thirty-one patients underwent two sets of oblique sagittal T2-weighted fast spin-echo sequences to evaluate the ACL. One oblique was prescribed from a coronal localizing sequence, while the other was prescribed off an axial series. Objective (average number of images to demonstrate ACL) and subjective (radiologist's confidence level) evaluations of both sequences were performed independently of the other and then comparatively by two radiologists. The coronally prescribed sagittal oblique was subjectively preferred in 18 patients, the axially prescribed oblique was preferred in one patient, and both sequences were felt to be equivalent in 12 patients. In 13 intact ligaments, the average number of images clearly demonstrating the entire length of the ACL was 1.77 on the coronally prescribed sequence and 1.31 on the axially prescribed images. Oblique sagittal images prescribed off a coronal localizer are both subjectively and objectively more effective than axially prescribed sagittal obliques in evaluating the ACL.


Subject(s)
Anterior Cruciate Ligament/pathology , Knee/pathology , Magnetic Resonance Imaging/methods , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged
14.
J Forensic Sci ; 45(2): 265-6, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10782945

ABSTRACT

T. Dale Stewart's contributions had a considerable influence on the development and early evolution of the field of forensic anthropology. This composition provides a perception of Stewart from the viewpoint of an advanced graduate student and then a young colleague. It explains, in part, the quiet leadership and assistance that Stewart provided at various professional and familiar levels to one individual and is indicative of the broad effect that Stewart had on generations of students and professionals in anthropology, osteology and forensic anthropology.


Subject(s)
Forensic Anthropology/history , History, 20th Century , Humans , Interprofessional Relations , Leadership , Mentors , United States
15.
J Clin Periodontol ; 27(4): 256-61, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10783839

ABSTRACT

BACKGROUND: Recent research has indicated that bacteria within a biofilm may undergo changes in susceptibility to antimicrobial agents when compared to planktonic forms. This study was conducted to determine the bactericidal effect of an essential oil-containing mouthrinse (Listerine Antiseptic) on dental plaque bacteria in situ. METHODS: 1-day-old plaque in 17 subjects was sampled at baseline from the buccal surfaces of diagonally contralateral maxillary and mandibular bicuspids and 1st molars. Subjects were then randomly assigned either an essential oil mouthrinse or a sterile saline negative control and rinsed under supervision with 20 ml for 30 s. 30 min later, plaque was sampled from the remaining contralateral posterior teeth. Subjects repeated these procedures with their respective alternate rinse after 1 week. Pooled plaque samples from each subject at each sampling period were stained with a commercially-available fluorescent stain which fluoresces live and dead bacteria green and red, respectively. The stained plaque specimens were analyzed using computerized image analysis. A separate in vitro study was conducted to determine the relationship between the % red stain per sample and bacterial viability. RESULTS: Analysis of vital stained plaque specimens indicated that following rinsing with the essential oil mouthrinse, 78.7% of bacteria were dead compared to 27.9% following rinsing with the negative control (p<0.001). The in vitro findings demonstrated that the % red stain per sample is reflective of actual bacterial kill. CONCLUSIONS: This study confirms the findings of previous in vitro and in vivo studies which demonstrated the essential oil mouthrinse to have significant biocidal activity against oral micro-organisms. These studies all support the primacy of a bactericidal mechanism in producing the plaque and gingivitis reductions observed in numerous clinical trials conducted on the essential oil mouthrinse.


Subject(s)
Anti-Infective Agents, Local/therapeutic use , Bacteria/drug effects , Dental Plaque/microbiology , Mouthwashes/therapeutic use , Oils, Volatile/therapeutic use , Salicylates/therapeutic use , Terpenes/therapeutic use , Bicuspid/microbiology , Biofilms/drug effects , Colony Count, Microbial , Cross-Over Studies , Dental Plaque/prevention & control , Drug Combinations , Female , Fluorescent Dyes , Gingivitis/microbiology , Gingivitis/prevention & control , Humans , Image Processing, Computer-Assisted , Male , Molar/microbiology , Placebos , Single-Blind Method
16.
Int J Surg Investig ; 2(1): 17-25, 2000.
Article in English | MEDLINE | ID: mdl-12774334

ABSTRACT

BACKGROUND: In the Spontaneously Hypertensive Rat (SHR), there is a significantly greater blood flow at the paw but not at the back than in the non-hypertensive Wistar Kyoto (WKY) rat. We wanted to assess the effect of this higher blood flow on wound healing at the paw. MATERIALS AND METHODS: We characterized the microvascular composition of wounds at the back and paw of 9 SHR rats and 10 WKY rats using a quantitative imaging program. Blood flow was compared using laser Doppler technology. RESULTS: The blood flow response to wounding at the back was identical in the SHR and WKY rats. There was an immediate sharp increase in flow at the center of the wound. Blood flow reached a peak at 3 days and then decreased somewhat by day 7, but still remained five-fold higher than the prewound baseline values. There was also a two-fold increase at the back wound perimeter. There were no differences in microvascular composition at the back between the SHR and WKY rats. In contrast, there was an immediate enormous increase in blood flow at paw wound center in the SHR rats. Flow increased to 75 ml/min/100 gm by 24 h then fell back sharply. Blood flow at the paw in the WKY rats changed very little over the 7 days post wounding. At 3 days, the flow was about twice as high in the SHR than in the WKY wound, but, by day 7, flow was similar in the two rat strains. At the SHR wound perimeter, there was a small increase in flow which was sustained through day 7. Although the microvascular composition at the paw wound center was similar in the SHR and WKY rats, there was a notable difference at the paw perimeter. At baseline, there was a slightly greater capillary density in the SHR paw (32 +/- 1 per mm3) than the WKY paw (25 +/- 8 per mm3). At 7 days after wounding, there was a substantial increase in capillary number in the SHR rats (48 +/- 8 per mm3) as compared to baseline (p = 0.05). In contrast, there was no significant difference in capillary number in the WKY paw wound perimeter (20 +/- 3 per mm3) as compared to baseline. CONCLUSIONS: There is a substantial difference in wound blood flow response between the hypertensive and the non-hypertensive rat. At the back, the blood flow effects of wounding are similar, but, at the paw, the SHR rat shows a dramatic transient increase in flow in the early phases of wound healing. There is apparently no capability to upmodulate microvascular resistance in response to increased pressure at this early stage of wound healing. However, within several days, the granulation tissue microvasculature becomes capable of controlling the effects of raised pressure in the SHR rat. In the SHR paw wound perimeter, there are significantly more capillaries than in the WKY rat. It is possible that greater capillary proliferation in the SHR rat results from higher blood flow in the early phase of wounding. The contrast between the WKY rat and the SHR rat serves to further illustrate the complexity of blood flow regulation which occurs during wound healing.


Subject(s)
Hypertension/physiopathology , Skin/blood supply , Wound Healing/physiology , Animals , Back , Blood Flow Velocity , Capillaries/pathology , Head , Hindlimb , Hypertension/pathology , Laser-Doppler Flowmetry , Microcirculation , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Skin/injuries , Vascular Resistance
17.
J Biochem ; 126(4): 708-14, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10502679

ABSTRACT

The spin state of the heme in superoxide (O(2)(.)(-))-producing cytochrome b(558) purified from pig neutrophils was examined by means of room-temperature magnetic circular dichroism (MCD) under physiological conditions. Cytochrome b(558) with varying amounts of low-spin and high-spin heme was prepared by either pH adjustment or heat treatment, and the O(2)(.)(-)-forming activity in a cell-free system was found to correlate with the low-spin heme content. The possibility that the O(2)(.)(-)-forming activity results from a transient high-spin ferric heme form that is induced during activation by anionic amphophils has also been investigated. EPR spectra of cytochrome b(558) activated by either arachidonic acid or myristic acid, showed that a transient high-spin ferric species accounting for approximately 50% of the heme appeared in the presence of arachidonic acid, but not in the presence of myristic acid. Hence the appearance of a transient high-spin ferric heme species on activation with an amphophil does not afford a common activation mechanism in the NADPH oxidase system. The EPR results for cytochrome b(558) activated with arachidonic acid showed that the transient high-spin ferric heme can bind cyanide. However, the high-spin ferric heme does not contribute to the O(2)(.)(-) production of cytochrome b(558) in cell-free assays in the presence of cyanide.


Subject(s)
Cytochrome b Group/chemistry , Heme/chemistry , NADPH Oxidases , Animals , Arachidonic Acid/pharmacology , Cell-Free System , Circular Dichroism , Cyanides/pharmacology , Cytochrome b Group/metabolism , Electron Spin Resonance Spectroscopy , In Vitro Techniques , Myristic Acid/pharmacology , Neutrophils/chemistry , Oxidation-Reduction , Superoxides/metabolism , Swine
18.
Comp Biochem Physiol A Mol Integr Physiol ; 122(4): 399-406, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10422258

ABSTRACT

The Spontaneously Hypertensive rat (SHR) and its non-hypertensive companion strain, the Wistar-Kyoto (WKY) rat, provide an excellent comparative model to permit study of the differential properties of cutaneous microvascular beds. We explored the possibility that chronically elevated vascular pressures in the SHR rat might affect the microvascular constitution of the skin. We measured skin blood flow at the back and at the paw of a group of 20-week-old WKY rats and a contrast group of SHR rats. We then performed skin biopsies at these two locations and used the NIH Image program to count and measure the size of capillaries, arterioles, and venules. We also determined microvascular density as percentage of total tissue area. At basal temperature, skin blood flow was similar in the two rat strains at both the back and paw. Heat induced vasodilatation resulted in a 50% increase in blood flow at the back, reaching the same level in the two rat groups. However, at the paw site, thermal stimulation resulted in significantly greater flow (39.3 +/- 3.1 ml/100 gm tissue per min) in the SHR rats than the WKY rats (28.6 +/- 1.9 ml/100 gm tissue per min, P < 0.05). The ratio of systemic arterial pressure to skin blood flow was computed as an index of vascular resistance to flow. At basal temperature, this index was 50% greater for the SHR rats at both skin sites. At 44 degrees C, the resistance index decreased at both sites in both rat groups but was still approximately 50% higher at the back of the SHR than the WKY rats. In contrast, the resistance index at 44 degrees C at the paw site fell to the same level in both the SHR and WKY rats. There were twice as many capillaries at the back of the WKY rats than at the back of the SHR rats (9.2 +/- 2.0 per mm2 vs. 4.7 +/- 1.2 per mm2, P < 0.05). Expressed as a percentage of total tissue area, the capillary density at the back in the WKY rats was 0.064 +/- 0.010% as compared to 0.034 +/- 0.008% in the SHR rats (P < 0.05). There were five times more arterioles at the paw compared to the back in both rat groups with no significant difference between the groups. We measured the diameter of the lumen and the thickness of the wall of each arteriole and computed their ratio as an index of possible media hypertrophy. There were minimal differences seen in these parameters between the two rat groups at the back and paw sites. The venular density was significantly higher at the paw than at the back in both rat groups with no significant difference between them. Reduced capillary density at the back of the SHR rats may be a developmental adaptation to high blood pressure. Such a reduction in the pathways of blood flow may help account for increased flow resistance at that site, independent of arteriolar vasoconstriction.


Subject(s)
Hypertension/physiopathology , Skin/blood supply , Analysis of Variance , Animals , Microcirculation/physiology , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Species Specificity
19.
J Clin Periodontol ; 26(7): 474-6, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10412853

ABSTRACT

Although laboratory studies are not necessarily predictive of clinical activity; they can help to elucidate mechanisms underlying clinical activity when the latter has been established. In a recent clinical study, an essential oil mouthrinse (Listerine Antiseptic) was shown to be significantly more effective than an amine fluoride/stannous fluoride mouthrinse (Meridol) in inhibiting supragingival plaque formation. This paper reports the results of laboratory studies comparing the antimicrobial effectiveness of these 2 mouthrinses using a kill kinetics assay and a plaque biofilm kill assay. In both assays, the essential oil mouthrinse was considerably more effective than the amine fluoride/stannous fluoride mouthrinse. These findings are consistent with the results of the clinical trial and may help to explain the observed differences in clinical activity.


Subject(s)
Amines/pharmacology , Anti-Infective Agents, Local/pharmacology , Bacteria/drug effects , Mouthwashes/pharmacology , Oils, Volatile/pharmacology , Salicylates/pharmacology , Terpenes/pharmacology , Tin Fluorides/pharmacology , Biofilms/drug effects , Candida albicans/drug effects , Coloring Agents , Dental Plaque/microbiology , Drug Combinations , Fusobacterium nucleatum/drug effects , Humans , Lacticaseibacillus casei/drug effects , Prevotella intermedia/drug effects , Saliva/microbiology , Streptococcus mutans/drug effects , Tongue/microbiology
20.
Clin Orthop Relat Res ; (365): 184-200, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10627703

ABSTRACT

Of 146 consecutive closed and Grade I open tibia shaft fractures treated with cast immobilization, external fixation, or intramedullary rod fixation during a 4-year period, 44 of 76 (58%) tibias of patients who smoked and 59 of 70 (84%) tibias of patients who did not smoke had followup to union or followup beyond 1 year. The demographics, fracture patterns, and treatments of the two groups were similar. Two of the 44 patients who smoked had nonunions at the 1-year followup, whereas none of the patients who did not smoke had nonunions. Of the 103 tibias with complete followup to union, the median time to clinical healing for patients who smoked (269 days) was significantly greater than that of patients who did not smoke (136 days). Likewise, there was a 69% delay in radiographic union in the group that smoked as interpreted by a radiologist blinded to the two groups. Statistical differences in clinical and radiographic healing rates between those who smoked and those who did not smoke were observed for patients receiving intramedullary fixation or external fixation. Statistical differences were not seen in the clinical and radiographic healing of tibias treated with cast immobilization, although tibias of patients who smoked took 62% longer to heal. The current data suggest that tibias of patients who smoke who require treatment with intramedullary nailing or external fixation require more time to heal than do those of patients who do not smoke.


Subject(s)
Fracture Healing/physiology , Smoking/adverse effects , Tibial Fractures/physiopathology , Adult , Aged , Casts, Surgical , Chi-Square Distribution , External Fixators , Female , Follow-Up Studies , Fracture Fixation , Fracture Fixation, Intramedullary , Fractures, Closed/diagnostic imaging , Fractures, Closed/physiopathology , Fractures, Open/classification , Fractures, Open/diagnostic imaging , Fractures, Open/physiopathology , Fractures, Ununited/diagnostic imaging , Fractures, Ununited/physiopathology , Humans , Male , Middle Aged , Radiography , Regression Analysis , Single-Blind Method , Tibial Fractures/classification , Tibial Fractures/diagnostic imaging , Time Factors
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