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1.
Int J Qual Health Care ; 32(9): 625-638, 2020 Nov 16.
Article in English | MEDLINE | ID: mdl-32901816

ABSTRACT

PURPOSE: Patient safety has developed as a strong marker for healthcare quality. Safety matters are important in the intensive care unit (ICU) where complex clinical decisions are made, intensive technology is used, and families hold a unique role. The aim of this review was to identify and describe factors that influence family member's perceptions of safety in the adult ICU. DATA SOURCES: Searches were conducted between September and November 2018 and repeated in July 2020 using CINAHL, MEDLINE (EBSCO), PubMed and PsycINFO databases. STUDY SELECTION: Published primary studies undertaken in adult ICUs and involving adult family member participants exploring safety or feeling safe. No date restrictions were applied. DATA EXTRACTION: A data extraction form collected information about sample, study design, data collection methods and results from each paper. Methodological quality was assessed using the QualSyst tools for qualitative and quantitative studies. Narrative synthesis was undertaken. RESULTS OF DATA SYNTHESIS: Twenty papers were included with 11 papers published since 2010. The majority of papers reported on qualitative studies (n = 16). Four factors were identified that influenced whether family members felt that the patient was safe in ICU: family visiting, information and communication, caring and professional competence. CONCLUSION: In detailing specific practices that make families feel safe and unsafe in ICU, these review findings provide a structure for clinicians, educators and researchers to inform future work and gives opportunity for the family role in patient safety to be reconsidered.


Subject(s)
Family , Intensive Care Units , Adult , Humans , Patient Safety , Qualitative Research , Quality of Health Care
2.
J Dent Res ; 98(8): 888-895, 2019 07.
Article in English | MEDLINE | ID: mdl-31126205

ABSTRACT

The temporomandibular joint (TMJ) disc nutrient environment profoundly affects cell energy metabolism, proliferation, and biosynthesis. Due to technical challenges of in vivo measurements, the human TMJ disc extracellular nutrient environment under load, which depends on metabolic rates, solute diffusion, and disc morphometry, remains unknown. Therefore, the study objective was to predict the TMJ disc nutrient environment under loading conditions using combined experimental and computational modeling approaches. Specifically, glucose consumption and lactate production rates of porcine TMJ discs were measured under varying tissue culture conditions (n = 40 discs), and mechanical strain-dependent glucose and lactate diffusivities were measured using a custom diffusion chamber (n = 6 discs). TMJ anatomy and loading area were obtained from magnetic resonance imaging of healthy human volunteers (n = 11, male, 30 ± 9 y). Using experimentally determined nutrient metabolic rates, solute diffusivities, TMJ anatomy, and loading areas, subject-specific finite element (FE) models were developed to predict the 3-dimensional nutrient profiles in unloaded and loaded TMJ discs (unloaded, 0% strain, 20% strain). From the FE models, glucose, lactate, and oxygen concentration ranges for unloaded healthy human TMJ discs were 0.6 to 4.0 mM, 0.9 to 5.0 mM, and 0% to 6%, respectively, with steep gradients in the anterior and posterior bands. Sustained mechanical loading significantly reduced nutrient levels (P < 0.001), with a critical zone in which cells may die representing approximately 13.5% of the total disc volume. In conclusion, this study experimentally determined TMJ disc metabolic rates, solute diffusivities, and disc morphometry, and through subject-specific FE modeling, revealed critical interactions between mechanical loading and nutrient supply and metabolism for the in vivo human TMJ disc. The results suggest that TMJ disc homeostasis may be vulnerable to pathological loading (e.g., clenching, bruxism), which impedes nutrient supply. Given difficulties associated with direct in vivo measurements, this study provides a new approach to systematically investigate homeostatic and degenerative mechanisms associated with the TMJ disc.


Subject(s)
Energy Metabolism , Nutrients , Temporomandibular Joint Disc/metabolism , Adult , Animals , Biomechanical Phenomena , Diffusion , Glucose , Humans , Lactic Acid , Male , Oxygen , Stress, Mechanical , Swine , Young Adult
3.
Adv Exp Med Biol ; 1117: 131-147, 2019.
Article in English | MEDLINE | ID: mdl-30980357

ABSTRACT

Anticancer peptides (ACPs) are cationic amphipathic peptides that bind to and kill cancer cells either by a direct- or indirect-acting mechanism. ACPs provide a novel treatment strategy, and selected ACPs are currently in phase I clinical trials to examine their safety and overall benefit in cancer patients. Increasing the selectivity of ACPs is important so that these peptides kill cancer cells without harming normal cells. Peptide sequence modifications may help to improve ACP selectivity. ACPs also have immune-modulatory effects, including the release of danger signals from dying cancer cells, induction of chemokine genes, increasing T-cell immune responses, and inhibiting T regulatory cells. These effects ultimately increase the potential for an effective anticancer immune response that may contribute to long-term benefits and increased patient survival. Packaging ACPs in nanoparticles or fusogenic liposomes may be beneficial for increasing ACP half-life and enhancing the delivery of ACPs to tumor target cells. Additionally, engineering ACP-producing oncolytic viruses may be an effective future treatment strategy. Overall research in this area has been slow to progress, but with ongoing ACP-based clinical trials, the potential for ACPs in cancer treatments is closer to being realized. The integration of basic research with computer modeling of ACPs is predicted to substantially advance this field of research.


Subject(s)
Antineoplastic Agents/pharmacology , Neoplasms/therapy , Peptides/pharmacology , Cations , Clinical Trials as Topic , Humans
4.
Science ; 363(6425): 367-374, 2019 01 25.
Article in English | MEDLINE | ID: mdl-30538164

ABSTRACT

In 2018, Kilauea Volcano experienced its largest lower East Rift Zone (LERZ) eruption and caldera collapse in at least 200 years. After collapse of the Pu'u 'O'o vent on 30 April, magma propagated downrift. Eruptive fissures opened in the LERZ on 3 May, eventually extending ~6.8 kilometers. A 4 May earthquake [moment magnitude (M w) 6.9] produced ~5 meters of fault slip. Lava erupted at rates exceeding 100 cubic meters per second, eventually covering 35.5 square kilometers. The summit magma system partially drained, producing minor explosions and near-daily collapses releasing energy equivalent to M w 4.7 to 5.4 earthquakes. Activity declined rapidly on 4 August. Summit collapse and lava flow volume estimates are roughly equivalent-about 0.8 cubic kilometers. Careful historical observation and monitoring of Kilauea enabled successful forecasting of hazardous events.

5.
J Dent Res ; 96(6): 647-653, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28530471

ABSTRACT

It is estimated that 2% to 4% of the US population will seek treatment for temporomandibular joint (TMJ) symptoms, typically occurring with anterior disc displacement. The temporomandibular retrodiscal tissue (RDT) has been postulated to restrict pathologic disc displacement. To elucidate RDT function, understanding regional RDT biomechanics and ultrastructure is required. No prior biomechanical analysis has determined regional variations in RDT properties or associated biomechanical outcomes with regional variations in collagen and elastin organization. The purpose of this study was to determine direction- and region-dependent tensile biomechanical characteristics and regional fibrillar arrangement of porcine RDT. Incremental stress relaxation experiments were performed on 20 porcine RDT specimens, with strain increments from 5% to 50%, a ramp-strain rate of 2% per second, and relaxation periods of 2.5 min. Tensile characteristics were determined between temporal and condylar regions and anteroposterior and mediolateral directions. RDT preparations were imaged using second-harmonic generation (SHG) microscopy for both collagen and elastin. Young's modulus showed significant differences by region ( P < 0.001) and strain ( P < 0.001). Young's modulus was <1 MPa from 5% to 20% strain, before increasing from 20% to 50% strain to a maximum of 2.9 MPa. Young's modulus trended higher in the temporal region and mediolateral direction. Instantaneous and relaxed moduli showed no significant difference by region or direction. Collagen arrangement was most organized near the disc boundary, with disorganization increasing posteriorly. Elastin was present at the disc boundary and RDT mid-body. Porcine RDT demonstrated region- and strain-dependent variations in tensile moduli, associated with regional differences in collagen and elastin. The small tensile moduli suggest that the RDT is not resistive to pathologic disc displacement. Further biomechanical analysis of the RDT is required to fully define RDT functional roles. Understanding regional variations in tissue stiffness and ultrastructure for TMJ components is critical to understanding joint function and for the long-term goal of improving TMJ disorder treatment strategies.


Subject(s)
Biomechanical Phenomena , Temporomandibular Joint Disc/physiology , Temporomandibular Joint Disc/ultrastructure , Animals , Elastic Modulus , Magnetic Resonance Imaging , Male , Stress, Mechanical , Swine , Tensile Strength
6.
J Oral Rehabil ; 44(7): 517-525, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28449265

ABSTRACT

Temporomandibular disorder (TMD) incidences are believed to be related to parafunctional behaviours like teeth clenching. This pilot study aimed to (i) develop an automated clench-detection algorithm, and (ii) apply the algorithm to test for differences in nocturnal clenching in women with and without TMD. Subjects gave informed consent to participate. Adult women were categorised using Diagnostic Criteria for TMD according to presence/absence (+/-) of both TM joint disc placement (DD) and chronic pain (P) into two groups (+DD+P, -DD-P) with 12 subjects each. Surface temporalis electromyography was recorded during oral tasks performed by subjects at two laboratory sessions. The data were used to characterise muscle activity per N of bite force (µV/N) for each subject, develop the clench-detection algorithm and test its accuracy. Ambulatory surface temporalis electromyography was self-recorded by each subject over three nights and analysed using the algorithm and bite force (N) versus muscle activity µV/N calibrations. Bonferroni-adjusted homoscedastic t-tests assessed for significant between-group differences in clenching (P < 0·05). Sensitivity, specificity and accuracy of algorithm-detected laboratory clenches were all ≥96%. During self-recordings 95% of clenches had durations of <4 s and peak forces of <10 N in both groups. Mean clench durations were significantly longer (P = 0·042) in +DD+P (1·9 ± 0·8 s) than -DD-P subjects (1·4 ± 0·4 s). Mean temporalis duty factors (%clench time/total recording time) were significantly larger (P = 0·041) in +DD+P (0·47 ± 0·34%) than -DD-P (0·26 ±0·22%) subjects. Nocturnal temporalis muscle activities detected by a validated algorithm were longer per clench and recording time in +DD+P compared to -DD-P women.


Subject(s)
Bite Force , Chronic Pain/physiopathology , Electromyography , Masseter Muscle/physiopathology , Muscle Contraction/physiology , Temporal Muscle/physiopathology , Temporomandibular Joint Disorders/physiopathology , Adult , Algorithms , Electromyography/methods , Female , Humans , Middle Aged , Missouri , Monitoring, Ambulatory , Pilot Projects , Polysomnography , Sleep , Temporomandibular Joint Disorders/complications , Temporomandibular Joint Disorders/diagnosis
8.
J Community Genet ; 8(1): 17-22, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27796853

ABSTRACT

The study aims to describe the logistics and results of a programme for newborn screening for sickle cell disease based on samples from the umbilical cord. Samples were dried on Guthrie cards and analysed by high pressure liquid chromatography. All suspected clinically significant abnormal genotypes were confirmed by age 4-6 weeks with family studies and then recruited to local sickle cell clinics. The programme has screened 66,833 samples with the sickle cell trait in 9.8 % and the HbC trait in 3.8 %. Sickle cell syndromes occurred in 407 babies (204 SS, 148 SC, 35 Sbeta+ thalassaemia, 6 Sbetao thalassaemia, 6 sickle cell-variants, 8 sickle cell-hereditary persistence of fetal haemoglobin) and HbC syndromes in 42 (22 CC, 14 Cbeta+ thalassaemia, 1 Cbetao thalassaemia, 5 HbC- hereditary persistence of fetal haemoglobin). Focusing on the year 2015, screening was performed in 15,408, compliance with sample collection was 98.1 %, and maternal contamination occurred in 335 (2.6 %) but in only 0.05 % did diagnostic confusion require patient recall and further tests. This model of newborn screening for sickle cell disease is accurate, robust and economic. It is hoped that it may be helpful for other societies with high prevalence of abnormal haemoglobins and limited resources, who are planning to embark on newborn screening for sickle cell disease.

9.
Anaesth Intensive Care ; 44(2): 262-9, 2016 Mar.
Article in English | MEDLINE | ID: mdl-27029659

ABSTRACT

A third of patients reviewed by rapid response teams (RRT) require end-of-life care. However, little is known about the characteristics and management of these patients following RRT review. This paper presents results of a retrospective, descriptive audit that explored the dying trajectory of adult ward inpatients who died outside of intensive care following RRT review. The study setting was a 430-bed tertiary New Zealand hospital during 2013. RRT, inpatient databases and hospital notes were used to identify 100 consecutive adult inpatients who died subsequent to RRT review. Outcome measures included time from RRT review to death, place of death, pre-existing co-morbidities and frequency of medical review. Results demonstrated that patients were old (median 77 years, IQR 63-85years), emergency admissions (n=100) and admitted under a medical specialty (n=71). All but one of the cohort had pre-existing co-morbidities (mean 3.2, SD 1.7), almost a third (n=31) had cancer and 51% had 1-4 previous inpatient admissions within the previous 12 months. The mean length of stay prior to RRT review was 4.9 days (SD 5.5) during which patients were frequently reviewed by senior medical staff (mean 6.8 times, SD 6.9, range 0-44). Twenty per cent of patients died after their first RRT review with a further 40% receiving treatment limitation/palliation. Fifty-two per cent of patients had a pre-existing DNAR. Eighty per cent of patients died in hospital. Whilst the RRT fulfils an unmet need in decision-making at end of life, there is a need to understand what RRT, instead of ward-based or palliative care teams, offers dying patients.


Subject(s)
Hospital Rapid Response Team , Terminal Care , Adult , Aged , Aged, 80 and over , Female , Humans , Length of Stay , Male , Middle Aged
11.
Collegian ; 23(4): 397-8, 2016.
Article in English | MEDLINE | ID: mdl-29116724
12.
Work ; 50(1): 21-36, 2015.
Article in English | MEDLINE | ID: mdl-25227672

ABSTRACT

BACKGROUND: The prevalence of medical risk factors for suicide (e.g., mental disorders, severe disability, social disruption) may be higher among WTs compared to traditional Army units. Likewise, the extent to which traditional factors that protect soldiers from developing serious mental disorders (e.g., social support, unit cohesion, leadership) are present among soldiers assigned to the WTU is unclear. OBJECTIVES: An epidemiological consultation (EPICON) was conducted in 2010 to assess potential causes for a perceived high rate of suicides and preventable deaths in U.S. Army Warrior Transition Units (WTUs) and to identify potential improvements to the system of care. METHODS OF STUDY: The EPICON focused on: (1) risk factors for suicide/preventable deaths; (2) chronic pain management; (3) utilization of and access to WTU medical and behavioral health (BH) services; and (4) the impact of the WTU environment on mission focus and warrior disposition. BH history was examined for soldiers who died by suicide or preventable death while assigned to the WTU (index cases) and a representative comparison group of non-index case soldiers. Surveys and focus groups were conducted at four WTUs with Warriors in Transition (WTs) and key support staff. RESULTS: The use of psychotropic and/or CNS depressant medications, prevalence of BH diagnoses and substance use disorders, polypharmacy, alcohol use, and a high cumulative number of stressors were identified as important risk factors for preventable deaths in the WTC. Areas of potential improvement to the system of care included addressing negative perceptions of the WTU environment, lack of social support, barriers to accessing BH services and issues related to coordination of care. CONCLUSIONS: There was no one single risk factor found to be associated with an increased likelihood of preventable deaths within the WTU. The unique design and operation of the WTUs as environments focused on treatment and rehabilitation provide both benefits and challenges to recovery and risk mitigation.


Subject(s)
Death , Military Personnel/statistics & numerical data , Rehabilitation Centers/standards , Adolescent , Adult , Case-Control Studies , Drug Overdose/mortality , Epidemiologic Studies , Female , Focus Groups , Humans , Male , Mental Disorders/complications , Middle Aged , Retrospective Studies , Risk Assessment/methods , Suicide/statistics & numerical data , Surveys and Questionnaires , United States/epidemiology , Suicide Prevention
13.
Bull Entomol Res ; 99(2): 193-206, 2009 Apr.
Article in English | MEDLINE | ID: mdl-18947454

ABSTRACT

Bemisia tabaci biotype B is a significant pest of agriculture world-wide. It was first detected in Australia in 1994. Assessments of the potential of parasitoids already present in Australia to control this pest indicated that two species of Eretmocerus and 11 species of Encarsia were present, but they did not exert sufficient control with a combined average of 5.0+/-0.3% apparent parasitism of 4th instars. Further, only 25% of samples containing biotype B had parasitised individuals present. The surveys also identified that fewer B biotype were being parasitised compared with the Australian indigenous biotype. Overall, Er. mundus was the most abundant parasitoid prior to the introduction. Previous research indicated that Er. hayati offered the best prospects for Australia and, in October 2004, the first releases were made. Since then, levels of apparent parasitism have averaged 29.3+/-0.1% of 4th instars with only 24% of collections having no parasitism present. Eretmocerus hayati contributed 85% of the overall apparent parasitism. In addition, host plants of the whitefly with low or no parasitism prior to the release have had an order of magnitude increase in levels of parasitism. This study covers the establishment of the case to introduce Er. hayati and the post-release establishment period November 2004-March 2008.


Subject(s)
Hemiptera/physiology , Hemiptera/parasitology , Pest Control, Biological , Wasps/physiology , Animals , Australia , Female , Host-Parasite Interactions , Male , Phylogeny , Plants/parasitology , Time Factors
14.
Mutat Res ; 492(1-2): 7-11, 2001 May 31.
Article in English | MEDLINE | ID: mdl-11377239

ABSTRACT

The relative mutagenic potentials of 11-amino-16,17-dihydro-15H-cyclopenta[a]phenanthrene, its 17-keto derivative, and 2- and 5-aminochrysene have been compared in Salmonella typhimurium TA98 and TA100 in the presence of a postmitochondrial liver preparation from Aroclor 1254 induced rats. The 11-amino hydrocarbon is a very weak mutagen (0.27 revertants/nmol), whereas the 11-amino-17-ketone is much more active (129 revertants/nmol). 2-Aminochrysene is the most mutagenic arylamine ( approximately 500 revertants/nmol) among these compounds, but its 5-amino isomer is much less active (0.9 revertants/nmol). Possible reasons for these marked differences are suggested. Use of TA98 with over-expressing O-acetyltransferase (YG 1024) and deficient in this enzyme (TA98/l,8-DNP(6)) with the 11-amino-17-ketone and with 5-aminochrysene clearly indicates the importance of this enzyme in their bioactivation, implying oxidation of the amino group to the hydroxylamine in both these compounds.


Subject(s)
Androstenes/toxicity , Chrysenes/toxicity , Mutagens/toxicity , Animals , Bay-Region, Polycyclic Aromatic Hydrocarbon , Male , Microsomes, Liver/drug effects , Microsomes, Liver/metabolism , Mutagenicity Tests , Rats , Rats, Wistar , Salmonella typhimurium/drug effects , Salmonella typhimurium/genetics , Structure-Activity Relationship
15.
Toxicology ; 161(3): 165-77, 2001 Mar 28.
Article in English | MEDLINE | ID: mdl-11297805

ABSTRACT

Whole homogenates of Agaricus bisporus metabolised the mushroom hydrazine agaritine [beta-N-(gamma-L(+)glutamyl)-4-(hydroxymethyl) phenylhydrazine] to generate at least three metabolites. None of these metabolites, however, was the free hydrazine [4-(hydroxymethyl)phenylhydrazine], the postulated metabolite of agaritine believed to be formed as a result of the loss of the gamma-glutamyl group, the reaction being catalysed by gamma-glutamyltransferase. The three metabolites of agaritine displayed weak mutagenic activity towards Salmonella typhimurium strain TA104. 4-(Hydroxymethyl)phenylhydrazine, as the N'-acetyl derivative, was metabolised by mushroom tyrosinase to yield a number of metabolites that induced a mutagenic response in S. typhimurium TA104. Similar to N'-acetyl-4-(hydroxymethyl)phenylhydrazine, agaritine was extensively metabolised by the mushroom tyrosinase but, in contrast, the structurally related N'-acetyl-4-hydrazinobenzoic acid did not serve as substrate of this enzyme, implying a critical role for the hydroxymethyl group at the para-position. In conclusion, the current studies have demonstrated for the first time that: (a) whole mushroom homogenates readily metabolise agaritine but not to the postulated 4-(hydroxymethyl)phenylhydrazine; and (b) mushroom tyrosinase metabolises agaritine and N'-acetyl-4-(hydroxymethyl)phenylhydrazine, in the latter case forming genotoxic metabolites.


Subject(s)
Agaricales/metabolism , Hydrazines/pharmacokinetics , Monophenol Monooxygenase/metabolism , Phenylhydrazines/pharmacokinetics , Agaricales/chemistry , Agaricales/enzymology , Biotransformation , Hydrazines/metabolism , Hydrazines/toxicity , Monophenol Monooxygenase/isolation & purification , Monophenol Monooxygenase/pharmacology , Mutagenicity Tests , Mutagens/metabolism , Mutagens/pharmacokinetics , Mutagens/toxicity , Phenylhydrazines/metabolism , Phenylhydrazines/toxicity
17.
J Org Chem ; 65(22): 7399-405, 2000 Nov 03.
Article in English | MEDLINE | ID: mdl-11076596

ABSTRACT

Using 500 MHz NMR, we have carried out a stable ion protonation and model nitration study of the methoxy-substituted hydrocarbon 6, its 15-ol 7, and the dimer 10, in order to evaluate OMe substituent effects on directing electrophilic attack and on charge delocalization mode/conformational aspects in the resulting carbocations. It is found that the C-11 methoxy group directs the electrophilic attack to C-12 and C-14. Thus protonation of 6 with FSO(3)H/SO(2)ClF gives a 4:1 mixture of monoarenium ions 6H(+)()/6aH(+)(). Prolonged reaction times and increased temperature induced fluorosulfonylation at C-14 (6(+)-SO(2)()F), whereas ambient nitration with NO(2)(+)BF(4)(-) occurred at C-12. The 15-ol derivative 7 is cleanly ionized to 11(+)(), providing the first example of an alpha-phenanthrene-substituted carbocation from phenanthrene C-1 position. Contrasting behavior of the D-ring methyl-substituted 9 and the C-11 methoxy-substituted 10 dimers is remarkable in that unlike 9 which is readily cleaved to produce the monomeric arenium ion 3H(+)(), 10 is diprotonated at the two C-12 sites and at C-12/C-14 in each unit. The latter dication-dimer exists as a mixture of diastereomers. Reactivity of 7 underscores the importance of 11(+)(). Attack at the C-14 ring junction is in concert with the proposal that electrophilic oxygen would attack at C-14/C-15 (epoxidation) followed by ring opening to give the biologically active 15-ol as a major metabolite.


Subject(s)
Phenanthrenes/chemical synthesis , Cations , Indicators and Reagents , Magnetic Resonance Spectroscopy , Models, Molecular , Phenanthrenes/chemistry , Solvents , Structure-Activity Relationship
18.
Mil Med ; 165(10): 751-6, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11050872

ABSTRACT

The ability to determine dental casualty rates for the Australian Defence Force in a given situation is vital for military planners. This article reviews the literature and the available Australian Defence Force data on the subject to give some guide to planners. The review found the studies to be fairly consistent in that a well-prepared dentally fit force can expect 150 to 200 dental casualties per 1,000 soldiers per year. If the force were less prepared, as in the case of a reserve call out, this figure would be likely to increase; in the extreme case of an ill-prepared force or a force assisting in humanitarian aid, the emergency rate could be five times that figure. The literature also indicates a change in the nature of dental casualties. Although maxillofacial cases have remained steady at 25%, dental disease has decreased and endodontic cases have had a corresponding increase.


Subject(s)
Military Personnel/statistics & numerical data , Stomatognathic Diseases/epidemiology , Warfare , Australia/epidemiology , Canada/epidemiology , Croatia/epidemiology , Emergency Medical Services/statistics & numerical data , Humans , Incidence , Military Dentistry/statistics & numerical data , Needs Assessment , Population Surveillance , Stomatognathic Diseases/etiology , Stomatognathic Diseases/prevention & control , United Kingdom/epidemiology , United States/epidemiology , Yugoslavia/epidemiology
19.
Nutr Cancer ; 37(1): 55-64, 2000.
Article in English | MEDLINE | ID: mdl-10965520

ABSTRACT

The fate of the mushroom hydrazine [14C]agaritine was investigated in the mouse and rat strains previously employed in carcinogenicity studies with the edible mushroom Agaricus bisporus. Agaritine was rapidly absorbed in both species, achieving higher blood levels in the mouse, but with similar area under the curve. Covalent binding of agaritine material to proteins was detected only in the liver and kidney, but the extent of binding was the same in the rat and mouse. Most of the radioactivity was excreted during the first 24 hours in both animal species: in the rat it was distributed equally between urine and feces, whereas in the mouse more of the radioactivity was excreted in the urine. No qualitative differences in the metabolic profile were evident, but quantitative differences were observed. Treatment of the urine with deconjugating enzymes did not reveal the presence of any conjugates. Agaritine, N'-acetyl-4-(hydroxymethyl)phenylhydrazine, and 4-(hydroxymethyl)benzene diazonium ion were not detected in the urine or in the plasma of either species. No mutagens or promutagens were detected by the Ames mutagenicity assay in the urine of either species after exposure to agaritine. Repeated administration of agaritine to rats and mice did not alter the urinary metabolic profile and excretion of radioactivity. Similarly, feeding mice a raw mushroom diet, according to the protocol employed in the carcinogenicity studies, did not modulate the excretion of radioactivity or the urinary metabolic pattern. No major species differences in the fate of agaritine in rat and mouse were noted that could provide a rationale for the carcinogenicity of A. bisporus in the mouse, but not in the rat.


Subject(s)
Agaricus , Kidney/metabolism , Liver/metabolism , Phenylhydrazines/pharmacokinetics , Animals , Area Under Curve , Feces/chemistry , Metabolic Clearance Rate , Mice , Models, Animal , Mutagenicity Tests , Phenylhydrazines/blood , Phenylhydrazines/urine , Protein Binding , Rats , Time Factors
20.
Mutat Res ; 465(1-2): 85-90, 2000 Feb 16.
Article in English | MEDLINE | ID: mdl-10708973

ABSTRACT

The title compound is a more potent carcinogen than would be anticipated from its simple phenanthrene structure lacking further D-ring conjugation. In vitro it undergoes microsomal metabolism to yield as major metabolites its 15- and 17-alcohols and its 16, 17-diol; other minor metabolites are also derived from attack at the 5-membered ring, but no evidence of aromatic oxidation is apparent. The title compound is a weak mutagen in the Ames' test with Salmonella typhimurium TA100, but only with microsomal bio-activation. The 17-ol and 16,17-diol are inactive, with or without biological activation. By contrast the 15-alcohol, a rather reactive compound, is a strong mutagen both in the presence and absence of the bio-activation system. This, therefore, may be the proximate carcinogen, and its structural analogy to the naturally occurring hepato-carcinogen safrole is noted.


Subject(s)
Androstenes/pharmacokinetics , Androstenes/toxicity , Carcinogens/pharmacokinetics , Carcinogens/toxicity , Androstenes/chemistry , Animals , Biotransformation , Carcinogens/chemistry , In Vitro Techniques , Male , Microsomes, Liver/metabolism , Mutagenicity Tests , Rats , Rats, Wistar , Salmonella typhimurium/drug effects , Salmonella typhimurium/genetics , Structure-Activity Relationship
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