Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 35
Filter
1.
N Z Vet J ; 69(6): 327-336, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34061718

ABSTRACT

AIMS: To assess potential cow-level risk factors for clinical mastitis during the dry period in cows infused with internal teat sealant (ITS) alone at drying off, and associations with elevated somatic cell counts (SCC) at the first herd test, or clinical mastitis in the subsequent lactation. METHODS: Ten herds reporting an incidence of clinical mastitis during the dry period of >3% amongst cows infused with ITS alone at the end of the 2018/2019 lactation were enrolled. Cow data collected included age, breed, milk yield and SCC at the last herd test before drying off, drying off date, clinical mastitis records during the dry period and in the subsequent lactation, and SCC at the first herd test following calving. RESULTS: Overall, 2,401 cows were infused with ITS alone and 196/2,401 (8.2%) cows were diagnosed with clinical mastitis during the dry period. In the final multivariable model for risk of clinical mastitis there was an interaction between age and milk yield at the last herd test (p < 0.001), with cows aged >4 years and producing ≥10 L/cow/day having a higher risk of clinical mastitis than younger cows or those producing <10 L/cow/day. The risk of clinical mastitis was higher for cows dried off in the last week of lactation than for cows dried off >1 week before the end of lactation for the herd (p = 0.033). The percentage of cows with elevated SCC (>150,000 cells/mL) at the first herd test in the following lactation was higher amongst those diagnosed with clinical mastitis over the dry period compared with those that were not (p = 0.048). The hazard of clinical mastitis in the first 60 days after calving was also higher in cows diagnosed with clinical mastitis in the dry period than those that were not (p < 0.001). CONCLUSIONS AND CLINICAL RELEVANCE: The risk of clinical mastitis in the dry period following infusion of ITS alone at the end of lactation was associated with cow age, milk yield before drying off and timing of drying off. Cows diagnosed with clinical mastitis over the dry period had a higher risk of clinical mastitis and of elevated SCC in the subsequent lactation. This was an observational study so no causal inferences can be made, however herdowners and veterinarians should follow current recommendations regarding management of milk yield before drying off, and selection of cows for treatment with ITS alone.


Subject(s)
Cattle Diseases , Mastitis, Bovine , Mastitis , Animals , Anti-Bacterial Agents/therapeutic use , Cattle , Cattle Diseases/drug therapy , Dairying , Female , Lactation , Mammary Glands, Animal , Mastitis/veterinary , Mastitis, Bovine/drug therapy , Mastitis, Bovine/epidemiology , Mastitis, Bovine/prevention & control , Milk , Risk Factors
2.
N Z Vet J ; 69(4): 211-223, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33960911

ABSTRACT

AIMS: To assess the effect on conception rate to first service, 3- and 6-week in-calf rates, final pregnancy rate and the hazard of pregnancy, of addition of a second prostaglandin (PG) injection 24 hours after the first, in a synchrony programme combining Ovsynch and progesterone in pasture-based dairy cows that had not been detected in oestrus before the start of the seasonal mating period. METHODS: This prospective, negative-controlled study was conducted using anoestrous cows (n = 1,411) from nine spring-calving dairy herds in the Waikato region of New Zealand. Ovaries of cows not detected in oestrus were examined by transrectal ultrasonography and the presence of a corpus luteum determined. All cows were then treated with an intravaginal progesterone-releasing device and injected I/M with gonadorelin (Day -9). Cows were injected I/M with cloprostenol at device removal (Day -2) and on Day -1 were injected with either water (single PG; n = 720), or cloprostenol (double PG; n = 692). On Day 0 cows were injected again with gonadorelin, unless previously detected in oestrus, and were inseminated on Day 1. Based on dated pregnancy diagnosis by transrectal ultrasonography, cows were categorised as conceiving to first insemination, becoming pregnant in the first 3 or 6 weeks, or becoming pregnant by the end of the mating period. RESULTS: Cows in the double PG group had increased conception rate to first service (45.3 (95% CI = 45.1-45.4)% vs. 41.1 (95% CI = 41.0-41.3)%; p < 0.001), 3-week in-calf rate (53.4 (95% CI = 53.6-54.0)% vs. 49.2 (95% CI = 49.0-49.4)%; p < 0.001), and 6-week in-calf rate (67.2 (95% CI = 65.7-68.8)% vs. 63.5 (95% CI = 62.0-65.0)%; p = 0.014) compared to cows in the single PG group. Final pregnancy rate and hazard of pregnancy did not differ between treatment groups (p >0.2). CONCLUSIONS: Addition of a second PG injection 24 hours after the first, increased conception rate to first service and the proportion of cows pregnant by 3 and 6 weeks after commencement of the mating period. CLINICAL RELEVANCE: Improved outcomes can be achieved when treating those cows not detected in oestrus by the start of the seasonal mating period by addition of a second PG injection to the currently recommended treatment protocol for these animals.


Subject(s)
Insemination, Artificial , Progesterone , Animals , Cattle , Female , Insemination, Artificial/veterinary , Pregnancy , Prospective Studies , Prostaglandins , Seasons
4.
Rev. colomb. ortop. traumatol ; 20(3): 40-47, sept. 2006. tab, ilus
Article in Spanish | LILACS | ID: lil-619319

ABSTRACT

Diseño del estudio: Cohorte descriptiva. Objetivo: Evaluar los resultados de una osteotomía reorientadora del acetábulo, diseñada por el autor, en 20 pacientes con displasia del desarrollo de la cadera, DDC (14 mujeres, 6 hombres). Materiales y métodos: El abordaje quirúrgico es el descrito para la osteotomía innominada de Salter. Se realiza un corte curvilíneo en el ilíaco con sierra de Gigli, desde la escotadura ciática mayor hasta un punto inmediatamente superior a la espina ilíaca antero inferior. Se desplaza el acetábulo en sentido anterior, lateral e inferior. No se utiliza injerto y se fi ja la osteotomía con clavos o tornillos, según tamaño y calidad ósea, de manera divergente o cruzada. Se inmoviliza con espica de yeso por 6 semanas. Resultados: Se encontró consolidación de la osteotomía en todos los pacientes a las 6 semanas post operatorias. El promedio de corrección del índice acetabular en el postoperatorio inmediato fue 16°; y a los 6 meses, de 13 °. El porcentaje de descubrimiento de la epífisis femoral antes de la cirugía fue del 25%; a los 6 meses de seguimiento no hubo descubrimiento de la cabeza femoral en ningún caso. A los dos años postoperatorios no se documento displasia. Recomendaciones: La osteotomía deslizante del acetábulo parece ser un procedimiento seguro. La corrección, en términos de índice acetabular y porcentaje de cubrimiento de la cabeza femoral, es adecuada y se mantiene en el tiempo. Además, no tiene el riesgo de colapso del injerto que existe con la osteotomía de Salter.


Subject(s)
Acetabulum , Bone Transplantation , Cohort Studies , Osteotomy
5.
Eur Respir J ; 22(5): 761-6, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14621082

ABSTRACT

Simple methods are needed to assess lung function in infants with cystic fibrosis (CF). This study determined the relationship between simple measurements obtained from tidal breathing with those from more complicated forced expiratory manoeuvres. Healthy infants and infants with CF were recruited from two maternity units and five specialist CF hospitals, respectively. Respiratory rate, tidal volume, minute ventilation and the tidal breathing ratio (TPTEF:TE) were measured in sedated infants and compared with forced expiratory volume in 0.4 seconds (FEV0.4) measured by the raised volume technique. Altogether, 95 healthy infants and 47 infants with CF of similar age, sex, ethnicity and proportion exposed to maternal smoking were recruited. There was no difference in TPTEF:TE and tidal volume between healthy infants and those with CF. Minute ventilation was significantly greater in infants with CF due to a mean (95% confidence interval) increase in respiratory rate of 5.8 (3.2-8.4) min(-1). Thirteen (28%) infants with CF had a respiratory rate elevated by >2 SD. However, no association between respiratory rate and FEV0.4 could be identified. Tidal breathing ratio was not useful in identifying diminished airway function in infants with cystic fibrosis. An elevated respiratory rate may be due in part to ventilation heterogeneity but is poorly predictive of diminished airway function measured by forced expiration.


Subject(s)
Cystic Fibrosis/physiopathology , Respiratory Function Tests , Child, Preschool , Female , Forced Expiratory Volume , Humans , Infant , Male , Tidal Volume
6.
Poult Sci ; 82(12): 1898-902, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14717547

ABSTRACT

Arcobacter butzleri is a causative agent of human enteritis that has been recently differentiated from the genus Campylobacter. Previous work suggests that its transmission to humans is likely through a foodborne route with a substantial tendency to be located on poultry carcasses. For reducing the incidence of this pathogen on commercial poultry, improved protocols are needed to sample and identify A. butzleri from infected birds prior to slaughter. The purpose of this study was to compare sampling methods for this emerging pathogen from chickens that were artificially inoculated per os with A. butzleri. We tested three sampling techniques commonly used to determine the microbiological quality of poultry: cloacal swabs, fecal samples, and environmental surface (drag) swabs collected when birds were 3, 5, or 7 wk old. These samples were cultured in Johnson-Murano enrichment broth and analyzed by PCR. Results indicate that environmental surface swabs yielded the highest recovery percentage. A detection rate of 75 to 100% was observed for each sampling period (age of chicken). Additionally, A. butzleri could not be isolated from the intestinal tract (jejunum, ileum, cecum, colorectum) of inoculated birds.


Subject(s)
Arcobacter/isolation & purification , Chickens/microbiology , Specimen Handling/veterinary , Animals , Arcobacter/genetics , Cloaca/microbiology , Environment , Feces/microbiology , Housing, Animal , Intestines/microbiology , Polymerase Chain Reaction , Specimen Handling/methods
7.
Pediatr Pulmonol ; 33(6): 419-28, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12001274

ABSTRACT

The raised volume rapid thoraco-abdominal compression technique (RVRTC) is being increasingly used to assess airway function in infants, but as yet no consensus exists regarding the equipment, methods, or analysis of recorded data. The aim of this study was to explore the relationship between maximal flow at functional residual capacity (V'(maxFRC)) and parameters derived from raised lung volumes, and to address analytical aspects of the latter technique in an attempt to assist with future standardization initiatives. Forced vital capacity (FVC) from lung volume raised to 3 kPa, timed forced expiratory volumes (FEV(t)), and forced expiratory flow parameters at different percentages of expired FVC (FEF(%)) were measured in 98 healthy infants (1-69 weeks of age). V'(maxFRC) using the tidal rapid thoraco-abdominal compression (RTC) technique was also measured. The within-subject relationships and within-subject variability of the various parameters were assessed. Duration of forced expiration was < 0.5 sec in 5 infants, meaning that FEV(0.3) and FEV(0.4) were the only timed volume parameters that could be calculated in all infants during the first months of life, and even when it could be calculated, FEV(0.5) approached FVC in many of these infants. It is recommended that FEV(0.4) be routinely reported in infants less than 3 months of age. Contrary to previous reports, within subject variability of V'(maxFRC) was less than that of FEF(75) (mean CV = 6.3% and 8.9%, respectively).A more standardized protocol when analyzing data from the RVRTC would facilitate comparisons of results between centers in the future.


Subject(s)
Functional Residual Capacity , Infant, Newborn/physiology , Respiratory Mechanics , Crown-Rump Length , Forced Expiratory Flow Rates , Humans , Vital Capacity
8.
Lancet ; 358(9297): 1964-5, 2001 Dec 08.
Article in English | MEDLINE | ID: mdl-11747924

ABSTRACT

The lung function of infants with cystic fibrosis is often reduced shortly after diagnosis. We measured the airway function of newly diagnosed infants to test whether this reduction is independent of clinically recognised lower respiratory illness. We compared the airway function of 33 infants with cystic fibrosis and 87 healthy controls after adjustment for sex, age, bodyweight and length, and exposure to maternal smoking. Airway function was significantly reduced in children with cystic fibrosis, even in those without clinically recognised previous lower respiratory illness. Our findings raise important questions about the onset and natural history of impaired airway function in infants with cystic fibrosis.


Subject(s)
Cystic Fibrosis/physiopathology , Lung/physiology , Case-Control Studies , Female , Humans , Infant , Male , Respiratory Function Tests , Respiratory Mechanics/physiology
9.
Intensive Care Med ; 27(11): 1788-97, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11810124

ABSTRACT

OBJECTIVE: The use of respiratory mechanics to optimise ventilator settings has become more common since the integration of pressure and flow transducers into modern ventilators. However, values of respiratory resistance (R(rs)) and compliance (C(rs)) can be overestimated in the presence of tracheal tube leak and clinical decisions based on these figures would be misinformed. This study aimed to assess the influence of tracheal tube leak on measurements of C(rs), R(rs) and expired tidal volume (V(TE)) in ventilated children in order to establish when such measurements were reliable in this population. DESIGN: Respiratory function was monitored for at least five consecutive hours during which normal medical procedures were performed. The magnitude and variability of tracheal tube leak was assessed during these periods. SETTING: The paediatric and cardiac intensive care units at Great Ormond Street Hospital for Children, NHS Trust, London. PATIENTS: Seventy-five paralysed, fully ventilated infants and children. RESULTS: Ten children had a mean leak greater than 20% (range: 22%-65%). Amongst this group there were wide fluctuations with respect to leak magnitude, V(TE), C(rs) and R(rs). Leaks of less than 20% appeared necessary to obtain reliable measurements of C(rs) and R(rs) and to ensure consistent and adequate ventilation. CONCLUSIONS: Leaks larger than 20% result in inconsistent tidal volume delivery and gross overestimation of C(rs) and R(rs) irrespective of ventilation mode. The magnitude of tracheal tube leak needs to be accurately displayed on all ventilatory equipment to verify reliable measures of respiratory function so that appropriate clinical decisions can be made and ventilatory management optimised.


Subject(s)
Intubation, Intratracheal , Respiration, Artificial , Respiratory Mechanics/physiology , Adolescent , Child , Child, Preschool , Equipment Failure , Female , Humans , Infant , Male , Monitoring, Physiologic , Respiratory Function Tests , Tidal Volume
10.
Infect Immun ; 67(3): 1521-5, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10024605

ABSTRACT

This study describes a quick (<12 h) assay for detecting temperature decreases in BALB/c and C57BL/6 mice injected intraperitoneally (i.p. ) with staphylococcal enterotoxin A (SEA), SEB, or SEC3 or toxic shock syndrome toxin 1 and a potentiating dose of lipopolysaccharide (LPS). Toxin-specific antisera effectively neutralized the temperature fluctuations in this model. Orally administered SEA or SEB (50 microg/animal), with or without LPS, did not have an effect on temperature or lethality. Versus wild-type mice, transgenic knockout mice lacking the p55 receptor for tumor necrosis factor (TNF) or gamma interferon were protected against an i.p. challenge of SEA plus LPS. The p75 receptor for TNF and intercellular adhesion molecule 1 have a negligible role in this toxic shock model.


Subject(s)
Bacterial Toxins , Body Temperature/drug effects , Enterotoxins/toxicity , Staphylococcus aureus/pathogenicity , Superantigens , Animals , Cytokines/blood , Lipopolysaccharides/toxicity , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout
11.
Paraplegia ; 32(3): 182-7, 1994 Mar.
Article in English | MEDLINE | ID: mdl-8008422

ABSTRACT

This study has attempted to ascertain the employment status of a group of 114 expatients with a traumatic spinal cord injury (SCI). The group was 1-7 years post injury. Out of the 114 subjects, 31% were in paid employment and 21% were either in full time education or training. There were 23% unemployed and seeking work and 25% unemployed and not seeking work. Occupations prior to the spinal cord injury were wide ranging throughout all employment categories, with the engineering and science category being most prevalent. Those in employment post injury showed a move towards the administration, clerical and finance categories, with science and engineering also providing some jobs.


Subject(s)
Employment , Occupations , Spinal Cord Injuries/rehabilitation , Adolescent , Adult , Age Distribution , Education , Female , Humans , Male , Middle Aged , Paraplegia , Quadriplegia , Sex Distribution , Surveys and Questionnaires
12.
Opt Lett ; 17(20): 1485, 1992 Oct 15.
Article in English | MEDLINE | ID: mdl-19798220
13.
Opt Lett ; 17(21): 1485, 1992 Nov 01.
Article in English | MEDLINE | ID: mdl-19798222
14.
Lab Invest ; 60(2): 286-95, 1989 Feb.
Article in English | MEDLINE | ID: mdl-2464718

ABSTRACT

Extracellular matrix (ECM) components of two glial fibrillary acidic protein positive (GFAP+) glioma lines U251 and UM6 were studied by silver stain, morphometry, immunofluorescence, enzyme-linked immunosorbent assay, and biosynthetic labeling. Both GFAP+ lines expressed the following qualitative features in common with previously studied GFAP-negative gliomas: (a) laminin, (b) type IV collagen, (c) extracellular fibrils of silver-reducing collagen (d) pattern of reactivity with lectins. Quantitative differences in GFAP+ glioma proteins included less collagen and more laminin than GFAP-negative gliomas. Sparse collagen of GFAP+ gliomas aggregated as extracellular masses. Individual cells of UM6 simultaneously expressed GFAP and mesenchymal ECM components. Results show qualitative similarities of ECM expression among GFAP+ and negative gliomas suggesting a common lineage of these two glioma cell types and universal expression of two epithelial components of ECM, laminin and type IV collagen, among cultured gliomas. Moreover, there is a diversity of quantity and type of ECM proteins of GFAP+ gliomas with the U251 line most restricted in its expression of ECM components and with UM6 manifesting markers of epithelial and mesenchymal lineage. This diversity suggests a capacity for regulation of phenotypic expression of ECM beyond that explained simply by the presence of two cell types of different lineage.


Subject(s)
Collagen/analysis , Extracellular Matrix/analysis , Glial Fibrillary Acidic Protein/analysis , Glioma/analysis , Enzyme-Linked Immunosorbent Assay , Fibronectins/analysis , Fluorescent Antibody Technique , Humans , Laminin/analysis , Staining and Labeling , Tumor Cells, Cultured
15.
Int J Cancer ; 37(6): 867-74, 1986 Jun 15.
Article in English | MEDLINE | ID: mdl-3519474

ABSTRACT

Five primary and 3 established human glioma cell lines were cultured with ascorbate and examined for expression of extracellular matrix components. All lines except C6 expressed collagen as assessed by silver impregnation, immunofluorescence and lectin staining and expressed laminin and fibronectin. None expressed a lectin marker for endothelial cells. Both epithelial and mesenchymal collagens were expressed. While extracellular components of glioma lines resembled those of fibroblasts more closely than other cell types, subtle differences between gliomas and fibroblasts were present. These included more laminin and collagen type-IV antigenic reactivity and more 11-12 nm diameter extracellular fibrils from individual gliomas, and slight differences in spectra of low-molecular-weight extracellular proteins assessed by gel electrophoresis. One primary and two established glioma lines analysed for DNA content were aneuploid in contrast to diploid fibroblasts. Simultaneous expression of mesenchymal and epithelial markers suggests a dual differentiation potential of glioma cells. Results do not support an endothelial origin for cells cultured from gliomas.


Subject(s)
Extracellular Matrix/metabolism , Glioma/metabolism , Neoplasm Proteins/metabolism , Carbohydrates/analysis , Cells, Cultured , Collagen/metabolism , DNA/analysis , DNA, Neoplasm/analysis , Fibroblasts/analysis , Fibronectins/metabolism , Fluorescent Antibody Technique , Humans , Laminin/metabolism , Microscopy, Electron
16.
Arch Sex Behav ; 14(4): 327-42, 1985 Aug.
Article in English | MEDLINE | ID: mdl-4051720

ABSTRACT

Vaginal photoplethysmography has been used to investigate sexual arousal response patterns in small samples of sexually functional and dysfunctional women, but selection of subjects for these studies has not been of a standardized nature. In the present study, two groups of women, who placed in either the upper or lower percentile ranks on the Sexual Arousal Inventory (Hoon et al., 1976a), were compared on a physiological measure of sexual arousal, vaginal pulse amplitude (VPA), during both waking erotic conditions and sleep. As hypothesized, no differences in VPA were found between groups during either waking or sleeping conditions. Contrary to expectation, groups also did not differ on subjective ratings of their laboratory arousal. With both groups combined, differences in VPA levels were evident between baseline and erotic conditions. Similarly, VPA levels differed between stages of sleep, with highest levels observed during rapid-eye-movement (REM) sleep. These findings suggest that self-reported low arousability is not based on lack of physiological response and that retrospective, self-report measures of sexual arousability differ in important ways from subjective and physiological measures of sexual arousal in the laboratory. In order to adequately assess sexual arousability, future researchers must either devise laboratory conditions that more closely resemble erotic stimuli occurring in subjects' natural environments or validate physiological measures of arousal in nonlaboratory settings. Finally, the nocturnal evaluation of VPA seems potentially useful for cases in which organic factors may be contributing to sexual dysfunction.


Subject(s)
Libido/physiology , Vagina/blood supply , Adult , Environment , Erotica , Fantasy , Female , Humans , Plethysmography , Sexual Dysfunction, Physiological/diagnosis , Sleep/physiology
17.
Am J Psychiatry ; 142(8): 905-10, 1985 Aug.
Article in English | MEDLINE | ID: mdl-4025585

ABSTRACT

To test the hypothesis that young depressed patients have prolonged rather than shortened sleep, 14 depressed patients aged 17-25 and age-matched normal control subjects were allowed to sleep as long as they wanted. All subjects increased their sleep over baseline values, but the extended sleep period of the depressed patients was almost twice as long as that of the control subjects. The distribution of sleep stages in the extended period did not differ. The depressed patients had changes in the length of REM periods similar to those of older subjects. The findings suggest an interaction between age, sleep, and depression.


Subject(s)
Depressive Disorder/complications , Disorders of Excessive Somnolence/complications , Sleep Wake Disorders/complications , Adolescent , Adult , Age Factors , Depressive Disorder/physiopathology , Depressive Disorder/psychology , Disorders of Excessive Somnolence/physiopathology , Disorders of Excessive Somnolence/psychology , Electroencephalography , Humans , Personality Inventory , Sleep/physiology , Sleep, REM/physiology
18.
Mutat Res ; 135(2): 97-103, 1984 Feb.
Article in English | MEDLINE | ID: mdl-6363917

ABSTRACT

A number of polycyclic aromatic sulfur heterocycles have been identified in coal-derived products and in shale oils. The mutagenic activity of some of these compounds, including dibenzothiophene, benzo[b]naphtho[1,2-d]thiophene, benzo[b]naphtho[2,1-d]thiophene and benzo[b]naphtho[2,3-d]thiophene have been determined using the Salmonella/microsome mutagenicity test. These compounds demonstrated either very weak or no mutagenic activity. The methyl derivatives of each of these four compounds were assayed for mutagenic activity. Salmonella typhimurium TA98 was used as the tester strain. All assays required a rat-liver homogenate metabolic activator. Five of the methylated derivatives, 1-methylbenzo[b]naphtho[1,2-d]thiophene, 3-methylbenzo[b]naphtho[1,2-d]thiophene, 1-methylbenzo[b]-naphtho[2,1-d]thiophene, 6-methylbenzo[b]naphtho[2,1-d]thiophene and 4-methylbenzo[b]naphtho[2,3-d]thiophene demonstrated mutagenic activity. However, activity was observed only at high concentrations of the metabolic activator.


Subject(s)
Mutagens/toxicity , Mutation , Thiophenes/toxicity , Animals , Biotransformation , Microsomes, Liver/metabolism , Mutagenicity Tests , Salmonella typhimurium/drug effects , Structure-Activity Relationship
19.
Environ Mutagen ; 6(4): 497-515, 1984.
Article in English | MEDLINE | ID: mdl-6381040

ABSTRACT

The isomers of various two-, three-, and four-ring amino polycyclic aromatic hydrocarbons were tested for mutagenic activity using a microbial plate incorporation test with four Salmonella typhimurium strains (TA98, TA100, TA1535, and TA1537). All compounds were assayed with an S9 metabolic activating enzyme system. The two-ring compounds were tested only with TA98. All were weakly mutagenic (1-10 rev/micrograms) except 2-aminobiphenyl, which was not mutagenic under these test conditions. All except two of the 13 fused three-ring compounds (aminofluorenes, aminoanthracenes, and aminophenanthrenes) were active frame shift mutagens; only the aminophenanthrenes were active base-pair mutagens. The potency of this group of isomeric compounds ranged from moderately (approximately 20 rev/microgram) to strongly (greater than 5,000 rev/microgram) mutagenic. As a group, the pericondensed four-ring amino compounds were the most mutagenic of the three groups tested. All of the aminofluoranthene and aminopyrene isomers showed significant mutagenic activity with TA98, TA100, and TA1537. In general, the mutagenic potency of the amino polycyclic aromatic compounds tested was highly dependent on the structural position of the amino group.


Subject(s)
Mutagens , Mutation , Polycyclic Compounds/toxicity , Animals , Biotransformation , Microsomes, Liver/metabolism , Mutagenicity Tests , Salmonella typhimurium/drug effects , Structure-Activity Relationship
20.
Mutat Res ; 117(1-2): 31-40, 1983 Apr.
Article in English | MEDLINE | ID: mdl-6188045

ABSTRACT

The stable isomers of 3- and 4-ring polycyclic aromatic sulfur heterocycles were tested for mutagenicity in the Ames standard plate incorporation test and a liquid pre-incubation modification of the Ames test. Of the 4 three-ring compounds tested, only naphtho[1,2-b]thiophene was mutagenic. Of the four-ring compounds, 7 of 13 were mutagenic in the standard Ames or pre-incubation Ames test. The highest activity for the 4-ring compounds was observed for phenanthrol[3,4-b]thiophene, a compound of approximately the same mutagenic potency in the Ames test as benzo[a]pyrene. The other active 4-ring compounds were of considerable less mutagenic potency than phenanthrol[3,4-b]thiophene. Mutagenicity for two of the 4-ring aromatic thiophenes could only be detected in the liquid pre-incubation Ames test. Salmonella typhimurium TA100 was the most sensitive strain to mutagenesis by these compounds, followed by TA98. All mutagenesis was indirect, requiring metabolic activation.


Subject(s)
Mutagens , Mutation , Polycyclic Compounds/toxicity , Animals , Biotransformation , Male , Microsomes, Liver/metabolism , Mutagenicity Tests , Polycyclic Compounds/metabolism , Rats , Rats, Inbred Strains , Salmonella typhimurium/drug effects , Structure-Activity Relationship , Sulfur
SELECTION OF CITATIONS
SEARCH DETAIL
...