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1.
HIV Med ; 21(3): 189-197, 2020 03.
Article in English | MEDLINE | ID: mdl-31821698

ABSTRACT

OBJECTIVES: SELPHI (HIV Self-Testing Public Health Intervention) is the largest randomized controlled trial (RCT) of HIV self-testing (HIVST) in a high-income setting to date, and has recruited 10 000 men who have sex with men (cis- and transgender) and transgender women who have sex with men. This qualitative substudy aimed to explore how those utilizing self-tests experience HIVST and the implications for further intervention development and scale-up. This is the first qualitative study in Europe investigating experiences of HIVST among intervention users, and the first globally examining the experience of using blood-based HIVST. METHODS: Thirty-seven cisgender MSM SELPHI participants from across England and Wales were purposively recruited to the substudy, in which semi-structured interviews were used to explore testing history, HIVST experiences and intervention preferences. Interviews were audio-recorded, transcribed and analysed through a framework analysis. RESULTS: Men accessed the intervention because HIVST reduced barriers related to convenience, stigma and privacy concerns. Emotional responses had direct links to acceptability. Supportive intervention components increased engagement with testing and addressed supportive concerns. HIVST facilitated more frequent testing, with the potential to reduce sexually transmitted infection (STI) screening frequency. Substudy participants with an HIV-positive result (n = 2) linked to care promptly and reported very high acceptability. Minor adverse outcomes (n = 2; relationship discord and fainting) did not reduce acceptability. Ease of use difficulties were with the lancet and the test processing stage. CONCLUSIONS: Intervention components shaped acceptability, particularly in relation to overcoming a perceived lack of support. The intervention was broadly acceptable and usable; participants expressed an unexpected degree of enthusiasm for HIVST, including those with HIV-positive results and individuals with minor adverse outcomes.


Subject(s)
Early Detection of Cancer/methods , HIV Infections/diagnosis , Homosexuality, Male/statistics & numerical data , Transgender Persons/statistics & numerical data , Adolescent , Adult , Developed Countries , England , Evaluation Studies as Topic , Female , Humans , Interviews as Topic , Male , Patient Acceptance of Health Care , Reagent Kits, Diagnostic , Self-Testing , Wales , Young Adult
2.
AIDS Behav ; 24(6): 1793-1806, 2020 Jun.
Article in English | MEDLINE | ID: mdl-31782068

ABSTRACT

The aim of this study is to investigate five hypothesized mechanisms of causation between depression and condomless sex with ≥ 2 partners (CLS2+) among gay, bisexual, and other men who have sex with men (GBMSM), involving alternative roles of self-efficacy for sexual safety and recreational drug use. Data were from the AURAH cross-sectional study of 1340 GBMSM attending genitourinary medicine clinics in England (2013-2014). Structural equation modelling (SEM) was used to investigate which conceptual model was more consistent with the data. Twelve percent of men reported depression (PHQ-9 ≥ 10) and 32% reported CLS2+ in the past 3 months. AURAH data were more consistent with the model in which depression was considered to lead to CLS2+ indirectly via low self-efficacy for sexual safety (indirect Beta = 0.158; p < 0.001) as well as indirectly via higher levels of recreational drug use (indirect Beta = 0.158; p < 0.001). SEM assists in understanding the relationship between depression and CLS among GBMSM.


Subject(s)
Depression , HIV Infections , Sexual Behavior , Sexual and Gender Minorities , Unsafe Sex , Adolescent , Adult , Condoms , Cross-Sectional Studies , Depression/epidemiology , England/epidemiology , Female , Homosexuality, Male , Humans , Latent Class Analysis , Male , Middle Aged , Risk-Taking , Sexual Partners , Young Adult
3.
Oncogene ; 38(10): 1751-1763, 2019 03.
Article in English | MEDLINE | ID: mdl-30353168

ABSTRACT

The role of extracellular vesicles (EVs) as vehicles for cell-to-cell communication between a tumour and its environment is a relatively new concept. The hypothesis that EVs may be critical in co-opting tissues by tumours to generate distant metastatic niches is particularly pertinent to prostate cancer (PCa), where metastatic-tropism to bone predominates over other tissue types. The potential role of EVs as a means of communication between PCa cells and cells of the bone stroma such as osteoblasts, is yet to be fully explored. In this study, we demonstrate that PCa cell EVs both enhance osteoblast viability and produce a significantly more supportive growth environment for PCa cells when grown in co-culture with EV-treated osteoblasts (p < 0.005). Characterisation of the RNA cargo of EVs produced by the bone-metastatic PCa cell line PC3, highlights the EV-RNA cargo is significantly enriched in genes relating to cell surface signalling, cell-cell interaction, and protein translation (p < 0.01). Using novel techniques to track RNA, we demonstrate the delivery of a set of PCa-RNAs to osteoblast via PCa-EVs and show the effect on osteoblast endogenous transcript abundance. Taken together, by using proof-of-concept studies we demonstrate for the first time the contribution of the RNA element of the PCa EV cargo, providing evidence to support PCa EV communication via RNA molecules as a potential novel route to mediate bone metastasis. We propose targeting PCa EVs could offer a potentially important preventative therapy for men at risk of metastatic PCa.


Subject(s)
Bone Neoplasms/secondary , Extracellular Vesicles/genetics , Osteoblasts/cytology , Prostatic Neoplasms/genetics , RNA/genetics , Bone Neoplasms/genetics , Cell Communication , Cell Line, Tumor , Cell Survival , Coculture Techniques , Humans , Male , Osteoblasts/metabolism , Tumor Microenvironment
4.
HIV Med ; 18(2): 89-103, 2017 02.
Article in English | MEDLINE | ID: mdl-27385511

ABSTRACT

OBJECTIVES: An increasing proportion of people living with HIV are older adults, who may require specialized care. Adverse physical and psychological effects of HIV infection may be greatest among older people or those who have lived longer with HIV. METHODS: The ASTRA study is a cross-sectional questionnaire study of 3258 HIV-diagnosed adults (2248 men who have sex with men, 373 heterosexual men and 637 women) recruited from UK clinics in 2011-2012. Associations of age group with physical symptom distress (significant distress for at least one of 26 symptoms), depression and anxiety symptoms (scores ≥ 10 on PHQ-9 and GAD-7, respectively), and health-related functional problems (problems on at least one of three domains of the Euroqol 5D-3L)) were assessed, adjusting for time with diagnosed HIV infection, gender/sexual orientation and ethnicity. RESULTS: The age distribution of participants was: < 30 years, 5%; 30-39 years, 23%; 40-49 years, 43%; 50-59 years, 22%; and ≥ 60 years, 7%. Overall prevalences were: physical symptom distress, 56%; depression symptoms, 27%; anxiety symptoms, 22%; functional problems, 38%. No trend was found in the prevalence of physical symptom distress with age [adjusted odds ratio (OR) for trend across age groups, 0.96; 95% confidence interval (CI) 0.89, 1.04; P = 0.36]. The prevalence of depression and anxiety symptoms decreased with age [adjusted OR 0.86 (95% CI 0.79, 0.94; P = 0.001) and adjusted OR 0.85 (95% CI 0.77, 0.94; P = 0.001), respectively], while that of functional problems increased (adjusted OR 1.28; 95% CI 1.17, 1.39; P < 0.001). In contrast, a longer time with diagnosed HIV infection was strongly and independently associated with a higher prevalence of symptom distress, depression symptoms, anxiety symptoms, and functional problems (P < 0.001 for trends, adjusted analysis). CONCLUSIONS: Among people living with HIV, although health-related functional problems were more common with older age, physical symptom distress was not, and mental health was more favourable. These results suggest that a longer time with diagnosed HIV infection, rather than age, is the dominating factor contributing to psychological morbidity and lower quality of life.


Subject(s)
Anxiety/epidemiology , Depression/epidemiology , HIV Infections/pathology , HIV Infections/psychology , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Surveys and Questionnaires , Time Factors , United Kingdom , Young Adult
5.
HIV Med ; 18(7): 463-473, 2017 08.
Article in English | MEDLINE | ID: mdl-28004523

ABSTRACT

OBJECTIVES: The aim of the study was to assess, among people living with HIV, knowledge of their latest HIV viral load (VL) and CD4 count. METHODS: Agreement between self-report and clinic record was assessed among 2771 HIV-diagnosed individuals on antiretroviral treatment (ART) in the UK Antiretrovirals, Sexual Transmission Risk and Attitudes Study (2011-2012). A confidential self-completed questionnaire collected information on demographic, socioeconomic, HIV-related and health-related factors. Participants were asked to self-report their latest VL [undetectable (≤ 50 copies/mL), detectable (> 50 copies/mL) or "don't know"] and CD4 count (< 200, 200-350, 351-500 or > 500 cells/µL, or "don't know"). Latest clinic-recorded VL and CD4 count were documented. RESULTS: Of 2678 participants on ART, 434 (16.2%) did not accurately report whether their VL was undetectable. Of 2334 participants with clinic-recorded VL ≤ 50 copies/mL, 2061 (88.3%) correctly reported undetectable VL; 49 (2.1%) reported detectable VL; 224 (9.6%) did not know their VL. Of 344 participants with clinic-recorded VL > 50 copies/mL, 183 (53.2%) correctly reported detectable VL; 76 (22.1%) reported undetectable VL; 85 (24.7%) did not know their VL. Of 2137 participants who reported undetectable VL, clinic-recorded VL was ≤ 50 copies/mL for 2061 (96.4%) and <1000 copies/mL for 2122 (99.3%). In analyses adjusted for gender/sexual orientation, ethnicity, age and time since starting ART, factors strongly associated with inaccurate self-report of VL (including "don't know") included socioeconomic disadvantage [prevalence ratio (95% CI) for "not" vs. "always" having enough money for basic needs: 2.4 (1.9, 3.1)], poor English fluency [3.5 (2.4, 5.1) vs. UK born], nondisclosure of HIV status [1.7 (1.3, 2.1)], ART nonadherence [2.1 (1.7, 2.7) for three or more missed doses vs. none in the past 2 weeks] and depressive symptoms (PHQ-9 score ≥ 10) [1.9 (1.6, 2.2)]. Overall, 612 (22.9%) of 2667 participants on ART did not accurately self-report whether or not their CD4 count was ≤ 350 cells/µL. CONCLUSIONS: There is a high level of accuracy of a self-report of undetectable VL in people on ART in the UK. Overall, accurate knowledge of personal VL level varied according to demographic, socioeconomic, HIV-related and health-related factors. Active identification of people who may benefit from increased levels of support and engagement in care is important.


Subject(s)
Anti-Retroviral Agents/therapeutic use , HIV Infections/drug therapy , HIV Infections/virology , Self Report , Viral Load , Adult , Aged , CD4 Lymphocyte Count , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Surveys and Questionnaires , United Kingdom , Young Adult
7.
Vet Microbiol ; 71(3-4): 193-200, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10703703

ABSTRACT

The antimicrobial sensitivities of 78 recent (1995-1998) canine isolates of Bordetella bronchiseptica from 13 separate sources were determined. Minimum inhibitory concentrations were assessed using the E-test method or by agar dilution. All 78 isolates were sensitive to tetracycline, doxycycline, enrofloxacin, and amoxycillin/clavulanic acid; the majority were sensitive to ampicillin (63/78; 81%), trimethoprim (57/78; 73%), and sulphadiazine (63/78; 81%). Plasmids were detected in 14 out of the 24 isolates tested. There was no correlation between the presence of plasmids and antibiotic resistance, but there was some correlation between the presence of plasmids and the origin of the isolates. Three sizes of plasmid were found: 20, 14, and 5.5 kb. Eight of the isolates contained all three plasmids, the remainder one or two, Thirteen isolates demonstrated beta-haemolysis, of which six produced a soluble haemolysin. Except for one isolate, haemolysin production correlated with plasmid carriage. Pulsed-field gel electrophoresis showed that all except one isolate could be grouped in the same genotype. Within this genotype isolates could be divided into three subtypes, generally corresponding to their place of origin.


Subject(s)
Bordetella Infections/veterinary , Bordetella bronchiseptica/drug effects , Dog Diseases/microbiology , Fluoroquinolones , Amoxicillin-Potassium Clavulanate Combination/pharmacology , Amoxicillin-Potassium Clavulanate Combination/therapeutic use , Ampicillin/pharmacology , Ampicillin/therapeutic use , Animals , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Anti-Infective Agents/pharmacology , Anti-Infective Agents/therapeutic use , Anti-Infective Agents, Urinary/pharmacology , Anti-Infective Agents, Urinary/therapeutic use , Bordetella Infections/drug therapy , Bordetella Infections/microbiology , Bordetella bronchiseptica/chemistry , Bordetella bronchiseptica/classification , DNA, Bacterial/chemistry , Dog Diseases/drug therapy , Dogs , Doxycycline/pharmacology , Doxycycline/therapeutic use , Drug Resistance, Microbial/genetics , Drug Therapy, Combination/pharmacology , Drug Therapy, Combination/therapeutic use , Electrophoresis, Gel, Pulsed-Field/veterinary , Enrofloxacin , Microbial Sensitivity Tests/veterinary , Penicillins/pharmacology , Penicillins/therapeutic use , Quinolones/pharmacology , Quinolones/therapeutic use , R Factors/isolation & purification , Sulfadiazine/pharmacology , Sulfadiazine/therapeutic use , Tetracycline/pharmacology , Tetracycline/therapeutic use , Trimethoprim/pharmacology , Trimethoprim/therapeutic use
8.
J Feline Med Surg ; 2(3): 123-33, 2000 Sep.
Article in English | MEDLINE | ID: mdl-11716607

ABSTRACT

A cross-sectional survey of a convenience sample of cats was carried out to determine the prevalence of and risk factors for respiratory tract disease, feline calicivirus (FCV) infection and feline herpesvirus (FHV) infection. Seven hundred and forty cats were studied; samples for isolation of FCV and FHV were obtained from 622 (84%). Data on individual cat and household variables were obtained by questionnaire for each cat and analysed using univariable and logistic regression analysis. Thirty-eight percent (282/740) of cats surveyed had respiratory tract disease. Eighteen of 24 predictor variables were found to be significantly (P<0.05) associated with the presence of respiratory tract disease in a cat on univariable analysis. Following logistic regression, several factors retained significance including isolation of FCV and FHV, younger cats (4-11 months of age) and multiple cat households. A negative association was found with breeding catteries and other types of household in comparison with rescue catteries. Overall, feline calicivirus was isolated from 162/622 (26%) of cats sampled; 33% of the cats with respiratory tract disease were FCV positive compared to 21% of healthy cats. Variables significantly associated with FCV isolation on logistic regression were the presence of respiratory tract disease and contact with dogs with and without respiratory tract disease. Feline herpesvirus was isolated from 30/622 (5%) of all cats sampled; 11% of cats with respiratory tract disease were FHV positive compared to 1% of healthy cats. Variables significantly associated with FHV isolation on univariable analysis included age, gender, and the presence of respiratory tract disease. Vaccination showed a negative association. Logistic regression analysis of the data for FHV was limited by the sample size and the low prevalence of FHV.


Subject(s)
Caliciviridae Infections/veterinary , Calicivirus, Feline , Cat Diseases/epidemiology , Herpesviridae Infections/veterinary , Respiratory Tract Infections/veterinary , Age Factors , Animals , Caliciviridae Infections/epidemiology , Caliciviridae Infections/etiology , Calicivirus, Feline/isolation & purification , Cat Diseases/etiology , Cat Diseases/virology , Cats , Cross-Sectional Studies , Female , Herpesviridae/isolation & purification , Herpesviridae Infections/epidemiology , Herpesviridae Infections/etiology , Logistic Models , Male , Odds Ratio , Prevalence , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/virology , Risk Factors , Surveys and Questionnaires , United Kingdom/epidemiology
9.
J Small Anim Pract ; 40(6): 252-6, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10404484

ABSTRACT

Feline Bordetella bronchiseptica infection had received little consideration until recent years when it has been increasingly documented in association with respiratory disease. This article reviews current knowledge on the organism; its epidemiology, pathogenesis, and clinical, diagnostic and therapeutic features.


Subject(s)
Bordetella Infections/diagnosis , Bordetella Infections/veterinary , Bordetella bronchiseptica , Cat Diseases/microbiology , Animals , Bordetella Infections/therapy , Cats
10.
J Small Anim Pract ; 40(6): 286-90, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10404490

ABSTRACT

A six-month-old kitten had congenital urethral sphincter mechanism incompetence due to urethral hypoplasia and associated uterine hypoplasia and vaginal aplasia. Diagnosis was based on radiographic examination, surgical exploration and histological examination of the lower urinary tract. Surgical correction resulted in a marked clinical improvement. The cat became fully continent following treatment with phenylpropanolamine.


Subject(s)
Urethra/abnormalities , Urethral Diseases/veterinary , Urinary Incontinence/veterinary , Vagina/abnormalities , Animals , Cats , Female , Laparotomy/methods , Laparotomy/veterinary , Phenylpropanolamine/administration & dosage , Radiography, Abdominal , Sympathomimetics/administration & dosage , Urethra/surgery , Urethral Diseases/diagnostic imaging , Urethral Diseases/surgery , Urinary Bladder/surgery , Urinary Incontinence/drug therapy , Urinary Incontinence/surgery
11.
Vet Rec ; 144(21): 575-80, 1999 May 22.
Article in English | MEDLINE | ID: mdl-10378288

ABSTRACT

A cross-sectional survey of a convenience-sample of 740 cats was undertaken to obtain an estimate of the prevalence of Bordetella bronchiseptica infection, and to identify risk factors that might predispose them to the infection. Data on individual cats and household variables, including disease status and animal contacts were obtained by questionnaire. B bronchiseptica was isolated from 82 (11 per cent) of the cats sampled. The prevalence of B bronchiseptica varied with the type of household sampled, being 19.5 per cent in rescue catteries, 9 per cent in breeding catteries, 13.5 per cent in research colonies, and 0 per cent in household pets. On the basis of a univariable analysis, 19 of 29 predictor variables were found to be significantly associated with the isolation of B bronchiseptica, including an association with cats in rescue catteries, and with cats from premises with larger numbers of animals. Separate analysis of the rescue cattery subpopulation showed a highly significant association on multivariable analysis with current respiratory disease, suggesting that different risk factors may operate in this type of environment. In the whole sample there was also strong association with cats from households containing a dog with recent respiratory tract disease. The clinical signs observed in the B bronchiseptica-positive cats included sneezing, ocular and nasal discharges and coughing, although only the association with sneezing was statistically significant. There was no significant association between the isolation of B bronchiseptica and the isolation of respiratory viruses, suggesting that in some circumstances B bronchiseptica may be able to cause disease independently.


Subject(s)
Bordetella Infections/veterinary , Bordetella bronchiseptica/isolation & purification , Cat Diseases/epidemiology , Analysis of Variance , Animals , Bordetella Infections/epidemiology , Bordetella Infections/microbiology , Cat Diseases/microbiology , Cats , Cross-Sectional Studies , Female , Logistic Models , Male , Prevalence , Risk Factors , Surveys and Questionnaires , United Kingdom/epidemiology
12.
Epidemiol Infect ; 120(2): 201-8, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9593491

ABSTRACT

A collection (164) of isolates of Bordetella bronchiseptica made predominantly from cats (132) but also from dogs (15), pigs (12) and other species was examined by pulsed field gel electrophoresis following macrorestriction digestion with XbaI. Each isolate was analysed twice and the patterns were entirely reproducible. The isolates fell into 17 different strains (> 3 bands different) and within strains there were numerous subtypes. Feline isolates fell into 12 of the 17 strains. In general, cats housed together had similar or identical strains and subtypes of B. bronchiseptica. There was no difference in the PFGE patterns of isolates made from carrier cats and those from cats with respiratory disease. Isolates from pigs and dogs were in general similar to the feline isolates and there was no great evidence for species specificity. The PFGE pattern of feline and canine isolates were more related to whether the animals were housed together rather than whether they came from dogs or cats.


Subject(s)
Bordetella Infections/microbiology , Bordetella bronchiseptica/classification , Carrier State/microbiology , Cat Diseases/microbiology , DNA, Bacterial/analysis , Dog Diseases/microbiology , Electrophoresis, Gel, Pulsed-Field , Restriction Mapping , Animals , Bordetella Infections/epidemiology , Bordetella Infections/veterinary , Carrier State/veterinary , Cat Diseases/epidemiology , Cats , Cluster Analysis , Dog Diseases/epidemiology , Dogs , Electrophoresis, Gel, Pulsed-Field/methods , Phylogeny , Reproducibility of Results , Restriction Mapping/methods , Serotyping
13.
J Small Anim Pract ; 38(10): 468-70, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9358410

ABSTRACT

An eight-year-old neutered male domestic shorthair cat had a zygomatic salivary cyst with associated mucocele formation. A fluctuating swelling developed ventral to the right eye, causing bulging of the lower eyeild, and a corresponding swelling was present in the caudal vestibule of the oral cavity. Cytological examination of the fluid obtained from aspiration of the swelling was consistent with the appearance of saliva. A tentative diagnosis of zygomatic salivary mucocele was made. Surgical exploration and resection of the swelling demonstrated the presence of a multilobular cystic zygomatic salivary gland. The histopathological appearance of the resected tissue was interpreted as an inflammatory reaction to mucus derived from a multilocular salivary cyst.


Subject(s)
Cat Diseases/pathology , Mucocele/veterinary , Salivary Gland Diseases/veterinary , Zygoma/pathology , Animals , Cat Diseases/surgery , Cats , Male , Mucocele/pathology , Mucocele/surgery , Salivary Gland Diseases/pathology , Salivary Gland Diseases/surgery , Zygoma/surgery
15.
Vet Microbiol ; 54(1): 63-72, 1997 Jan.
Article in English | MEDLINE | ID: mdl-9050171

ABSTRACT

One hundred and fifty-two predominantly feline isolates of Bordetella bronchiseptica were tested for their susceptibility to seven antimicrobial agents using an agar dilution method. The majority of isolates tested by the agar dilution method were resistant to trimethoprim (MIC90 500 micrograms/ml) and ampicillin (MIC90 > 32 micrograms/ml) but sensitive to tetracycline, doxycycline and enrofloxacin (MIC90 2 micrograms/ml for all three agents). The isolates showed a spectrum of susceptibility to sulphadiazine and clavulanate potentiated amoxycillin. The MIC's of twenty-nine of the 152 isolates were then compared for five of the antimicrobial agents using the E-test (AB Biodisk, Sweden), a recently introduced method for measuring the MIC's of antimicrobial agents based on the diffusion of a pre-defined antibiotic gradient from a plastic strip. Comparisons with the E-test demonstrated an overall agreement (+/- 1 log2 dilution) with the agar dilution method of 79.4% and an agreement within +/- 2 log2 dilutions of 96.2%.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bordetella bronchiseptica/drug effects , Cats/microbiology , Agar , Animals , Bordetella bronchiseptica/growth & development , Bordetella bronchiseptica/isolation & purification , Dogs , Microbial Sensitivity Tests/methods , Nasal Mucosa/microbiology , Oropharynx/microbiology , Rabbits , Swine
16.
J Antimicrob Chemother ; 40(6): 811-6, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9462432

ABSTRACT

Of 52 antibiotic-resistant Bordetella bronchiseptica isolates from cats, ten carried plasmids. Only two of these plasmids, pLV1400 and pLV1401, were self-transmissible to Escherichia coli K12; both plasmids encoded resistance to ampicillin, tetracycline, sulphonamides, streptomycin and mercuric chloride, and were of incompatibility group P (IncP). Transferable tetracycline resistance has not been reported in B. bronchiseptica previously. The plasmids were identical in size (c.51 kb), restriction endonuclease digestion pattern and gene sequences (trfA and korA) within the IncP replicon. The trfA and korA sequences differed from those of the archetypal IncP plasmids RP4 and R751. Although the two B. bronchiseptica isolates were from epidemiologically and geographically separated cats, pulsed-field gel electrophoresis of their XbaI- or DraI-digested chromosomal DNA indicated that they were genotypically identical. The plasmid-encoded ampicillin resistance was mediated by a penicillinase of molecular weight 49,000, and pI 8.45 which was inhibited by clavulanate (IC50 = 0.1 mg/L) and tazobactam (IC50 = 0.42 mg/L) but not by parachloromercuribenzoate or EDTA. The high-level tetracycline resistance was mediated by a class C efflux mechanism that has not been described previously in this genus. The presence of transferable multi-drug resistance on a promiscuous plasmid may limit options for therapy of respiratory tract infection in companion and farm animals.


Subject(s)
Bordetella bronchiseptica/genetics , R Factors/genetics , Tetracycline Resistance , Animals , Anti-Bacterial Agents/pharmacology , Bordetella bronchiseptica/drug effects , Cats , Microbial Sensitivity Tests
17.
Eur J Neurosci ; 2(6): 544-555, 1990.
Article in English | MEDLINE | ID: mdl-12106024

ABSTRACT

It has been shown that most hippocampal complex-spike cells fire at specific locations in relation to a set of controlled spatial cues and that they continue to fire in the appropriate places when the cues are removed (O'Keefe and Conway, 1978; O'Keefe and Speakman, 1987). However, the goal remained in a constant position relative to the controlled cues throughout these experiments. It is therefore possible that the unit firing was related to the goal location and not to the controlled cues as was suggested. For example, firing in a particular location might signal the rat's intention to make a particular turn towards the goal from that location and not the location itself. There are many reasons for believing that this is an unlikely class of explanations; nevertheless a test of this hypothesis was undertaken in the present experiment. Nineteen place units were recorded from three rats as they performed the task of finding the goal location. After obtaining an accurate picture of the place fields in relation to the controlled cues and the goal, the location of the goal relative to the cues was moved and the animal retrained to the new goal. After the new goal was being consistently chosen, a second picture of the place fields of the same units was obtained. If the fields were related to the environment created by the cues then they would remain the same during the two stages of the experiment. If they were related to the goal, or to the intended movements towards the goal, then they would rotate relative to the cues. As expected, the majority of place fields remained in the same place in relation to the cues during the two stages of the experiment and were not influenced by the goal relocation. In only two cases was there any suggestion that the place fields changed their location after the goal was moved. It was concluded that the activity of place cells is related to an animal's location in an environment and that the results accord with cognitive map theory of hippocampal function (O'Keefe and Nadel, 1978).

18.
Exp Brain Res ; 68(1): 1-27, 1987.
Article in English | MEDLINE | ID: mdl-3691688

ABSTRACT

Single unit activity was recorded from complex spike cells in the hippocampus of the rat while the animal was performing a spatial memory task. The task required the animal to choose the correct arm of a 4 arm plus-shaped maze in order to obtain reward. The location of the goal arm was varied from trial to trial and was identified by 6 controlled spatial cues which were distributed around the enclosure and which were rotated in step with the goal. On some trials these spatial cues were present throughout the trial (spatial reference memory trials) while on other trials they were present during the first part of the trial but were removed before the rat was allowed to choose the goal (spatial working memory trials). On these latter trials the animal had to remember the location of the cues and/or goal during the delay in order to choose correctly. 55 units were recorded during sufficient reference memory trials for the relationship between their firing pattern and different spatial aspects of the environment to be determined. 33 units had fields with significant relations to the controlled cues while 16 had significant relations to the static background cues, those cues in the environment which did not change position from trial to trial. Of 43 units which could be tested for their relation to the shape of the maze arms themselves, 15 showed such a relationship. Therefore the place units can be influenced by different aspects of the spatial environment but those related to the task requirement appear to be more potent. Interaction effects between the different spatial factors also influenced the firing pattern of some units. Of particular interest was the interaction between the controlled cues and the static background cues found in some cells since this might shed some light on how the hippocampus enables the rat to solve the memory task. 30 units with place fields related to the controlled cues were recorded during successful performance on spatial working memory trials as well as during spatial reference memory trials. The place fields of 90% of these units were maintained during the retention phase of the memory trials. During the recording of some units, other types of trial were given as well. On control trials, the cues were removed before the rat was placed on the maze. These trials provided controls for the potential influence of information left behind by the controlled cues and for the influence of the animal's behaviour on the unit activity.(ABSTRACT TRUNCATED AT 400 WORDS)


Subject(s)
Hippocampus/physiology , Memory/physiology , Space Perception/physiology , Animals , Cues , Electrophysiology , Hippocampus/cytology , Male , Rats , Rats, Inbred Strains
19.
Sci Prog ; 71(284 Pt 4): 511-30, 1987.
Article in English | MEDLINE | ID: mdl-3326169
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