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T Lambert

Publications and source records attributed to T Lambert.

At least 37 records · Page 2Linked to original sources
PubMed1999

Phylogenetic analysis of proteolytic Acinetobacter strains based on the sequence of genes encoding aminoglycoside 6'-N-acetyltransferases.

The sequence of seven aac(6')-I genes encoding aminoglycoside 6'-N-acetyltransferases from proteolytic Acinetobacter strains including genomic species 14, 15, 16, and 17 and from ungrouped proteolytic strains 631, 640, and BM2722 was determined. Pulsed-field gel electrophoresis of genomic DNA of these strains and of Acinetobacter sp. 6 CIP A165 digested with SfiI followed by hybridization with rRNA and aac(6')-I specific probes indicated that these genes were located in the chromosome. Phylogenetic analysis of the genes indicated that aac(6')-I of A. baumannii, Acinetobacter ungrouped strain 631, and Acinetobacter sp. 16 formed a cluster (91.5 to 92.3% identity) whereas aac(6')-I of Acinetobacter sp. 15, sp. 17, and Acinetobacter ungrouped strain BM2722 formed another cluster (90.7 to 94.6% identity). A third cluster was constituted by A. haemolyticus and Acinetobacter sp. 6 (83.6% identity). The phylogeny drawn from aac(6')-I sequences was consistent with that based on DNA-DNA hybridization and phenotype comparison. The aac(6')-I genes were all species specific except for aac(6')-Ih located in a 13.7-kb non conjugative plasmid from A. baumannii BM2686. We conclude that aac(6')-I genes may be suitable for identification at the species level and for analysis of the phylogenetic relationships of Acinetobacter.

Acetyltransferases↗
PubMed1999

Postpartum thyroid dysfunction: clinical assessment and relationship to psychiatric affective morbidity.

OBJECTIVE: Postpartum thyroid dysfunction (PPTD), diagnosed using biochemical criteria, is usually transient with a wide range of reported prevalence rates. The specific clinical and psychiatric morbidity associated with PPTD is still uncertain. The aims of the study were to determine the point prevalence of PPTD in Australian women at 6 months postpartum and to assess the specific clinical and psychiatric morbidity in these women. DESIGN: Women who were Caucasian, aged 20-45 years and 4.5-5.5 months postpartum, were randomly selected and invited into the study. The respondents were assessed for biochemical and psychiatric morbidity. PPTD for this study was defined as TSH or free T4 outside the adult reference range. A double blind clinical assessment of PPTD women and their matched controls used standardized clinical hypo- and hyperthyroid clinical indices. PATIENTS: From the total randomly selected sample size of 1816 women, 748 participated. MEASUREMENTS: Biochemical measurements were serum TSH, free T4, microsomal antibody (MsAb) and thyroid peroxidase antibody (TPOAb), and thyroid receptor antibodies (only in women with low TSH). Psychiatric assessment involved screening all participants using the General Health Questionnaire 28, followed by classifying and quantifying severity of cases using DSM-III-R categories for depression and anxiety. Clinical signs and symptoms of hypo- and hyper-thyroidism were measured using weighted standardized indices. Thyroid size was assessed by palpation. Achilles tendon reflex time was measured by photomotograph. RESULTS: The prevalence of PPTD in the participants was 11.5% (95% CI 9.2-13. 8%), giving a minimum prevalence for the randomly selected sample of 4.7% (95% CI 3.7-5.7%). In the PPTD women, 54% had an elevated TSH, 30% had a suppressed TSH and the remainder had a low fT4 and normal TSH. Positive thyroid autoantibody titres in the PPTD group were 46. 5% for microsomal antibody (MsAb) and 63.9% for thyroid peroxidase antibody (TPOAb), and in the non-PPTD group were 1.7% and 4.9%, respectively. The 6 month point prevalence rates of depression, generalized anxiety disorder and panic disorder and/or agoraphobia were 9.4%, 1.4% and 3.1%, respectively. No relationship was found between PPTD status and the diagnosis of current depression or between thyroid antibody status and current depression. In women who were diagnosed as anxious at the time of assessment, the number of anxiety symptoms was higher in the PPTD group (P < 0.05). There was no difference in signs and symptom scores for the hypo- and hyper-thyroid clinical indices between PPTD women and their controls. CONCLUSION: This study has shown a high prevalence of postpartum thyroid dysfunction but there was no difference in the clinical and psychiatric signs and symptoms between cases and controls. In the social, psychological, physical and endocrine setting of the postpartum period, women with postpartum thyroid dysfunction are identifiable by the attending physician only by their abnormal thyroid function tests.

Adult↗
PubMed1999

A double-blind, multicentre study to assess the tolerability and efficacy of paroxetine compared with amitriptyline in the treatment of depressed patients in Australian general practice.

OBJECTIVE: This study compared the tolerability and efficacy of paroxetine and amitriptyline in the treatment of depression in general practice. METHODS: In this double-blind, multicentre study conducted in the general practice, patients with depression (Montgomery Asberg Depression Rating Scale [MADRS] score > or = 20) who were regarded as requiring antidepressant therapy were randomly assigned to receive paroxetine (20 mg, n = 184) or amitriptyline (50-100 mg, n = 191) once daily for 9 weeks. RESULTS: More patients completed treatment with paroxetine than with amitriptyline (71.1% vs 56.1%, p = 0.009). Depression rating scores (MADRS and Clinical Global Impression [CGI]) were improved with both agents, but at week 9, paroxetine achieved more favourable scores compared with amitriptyline on MADRS (p=0.019), CGI severity of depression (p=0.044), and CGI efficacy index (p = 0.038). CONCLUSIONS: Depressed patients treated in general practice respond more quickly and are more likely to complete the treatment regimen with paroxetine than with amitriptyline.

Adult↗
PubMed1999

Characterization of the chromosomal aac(6')-Iz gene of Stenotrophomonas maltophilia.

The aac(6')-Iz gene of Stenotrophomonas maltophilia BM2690 encoding an aminoglycoside 6'-N-acetyltransferase was characterized. The gene was identified as a coding sequence of 462 bp corresponding to a protein with a calculated mass of 16,506 Da, a value in good agreement with that of ca. 16,000 found by in vitro coupled transcription-translation. Analysis of the deduced amino acid sequence indicated that the protein was a member of the major subfamily of aminoglycoside 6'-N-acetyltransferases. The enzyme conferred resistance to amikacin but not to gentamicin, indicating that it was an AAC(6') of type I. The open reading frame upstream from the aac(6')-Iz gene was homologous to the fprA gene of Myxococcus xanthus (61% identity), which encodes a putative pyridoxine (pyridoxamine) 5'-phosphate oxidase. Pulsed-field gel electrophoresis of total DNA from BM2690 and S. maltophilia ATTC 13637 digested with XbaI, DraI, and SpeI followed by hybridization with rRNA and aac(6')-Iz-specific probes indicated that the gene was located in the chromosome. The aac(6')-Iz gene was detected by DNA-DNA hybridization in all 80 strains of S. maltophilia tested. The MICs of gentamicin against these strains of S. maltophilia were lower than those of amikacin, netilmicin, and tobramycin, indicating that production of AAC(6')-Iz contributes to aminoglycoside resistance in S. maltophilia.

Acetyltransferases↗
PubMed1999

Activation of the cryptic aac(6')-Iy aminoglycoside resistance gene of Salmonella by a chromosomal deletion generating a transcriptional fusion.

Salmonella enterica subsp. enterica serotype Enteritidis BM4361 and BM4362 were isolated from the same patient. BM4361 was susceptible to aminoglycosides, whereas BM4362 was resistant to tobramycin owing to synthesis of a 6'-N-acetyltransferase type I [AAC(6')-I]. Comparative analysis of nucleotide sequences, pulsed-field gel electrophoresis patterns, and Southern hybridizations indicated that the chromosomal aac(6')-Iy genes for the enzyme in both strains were identical and that BM4362 derived from BM4361 following a ca. 60-kb deletion that occurred 1.5 kb upstream from the resistance gene. Northern hybridizations showed that aac(6')-Iy was silent in BM4361 and highly expressed in BM4362 due to a transcriptional fusion. Primer extension mapping identified the transcriptional start site for aac(6')-Iy in BM4362: 5 bp downstream from the promoter of the nmpC gene. Study of the distribution of aac(6')-Iy by PCR and Southern hybridization with a specific probe indicated that the gene, although not found in S. enterica subsp. arizonae, was specific for Salmonella. In this bacterial genus, aac(6')-Iy was located downstream from a cluster of seven open reading frames analogous to an Escherichia coli locus that encodes enzymes putatively involved in carbohydrate transport or metabolism. This genomic environment suggests a role in the catabolism of a specific sugar for AAC(6')-Iy in Salmonella.

Acetyltransferases↗
PubMed1998

A preliminary report: a new scale to identify the pseudodementia syndrome.

BACKGROUND: The literature was reviewed to abstract items which were claimed to distinguish organic dementia from pseudodementia. Their discriminating powers were tested in a prospective study. Eighteen of these items were selected to create a questionnaire which should distinguish organic dementia from pseudodementia. The gold standard was the final diagnosis given by a consultant psychiatrist 12-14 months later. METHOD: One hundred and twenty-eight patients referred to our service with a differential diagnosis of depressive pseudodementia were screened using a checklist of 44 characteristic features (in the form of questions with 'yes' or 'no' answers) which were claimed in the literature of differentiate between organic dementia and depressive pseudodementia. This checklist covers the areas of history, clinical data, insight and performance. RESULTS: Forty points (questions) out of the 44 in the checklist showed significant discriminating power to differentiate dementia from depressive pseudodementia (p < 0.01). A principal component and factor analysis was performed from which 18 questions were extracted. The shortened questionnaire was able to classify (43/44 cases) 98% of dementia cases and (60/63) 95% of depression correctly. A new definition has been introduced for 'pseudodementia' as a syndrome of reversible subjective or objective cognitive problems caused by non-organic disorder. Thus depressive pseudodementia may be classified into two subtypes. Type I is a group of patients who have depressive symptoms with subject complaint of dysmnesia without measurable intellectual deficits. Type II is a group of patients who have depressive symptoms and show poor cognitive performance based on poor concentration not due to organic disorder.

Aged↗
PubMed1998

Molecular epidemiology of aminoglycoside resistance in Acinetobacter spp.

Most aminoglycoside resistance in Acinetobacter spp. involves production of aminoglycoside-modifying enzymes. Previous studies have shown that the genes encoding these enzymes can be present on plasmids, transposons or within integron-type structures. To determine whether particular mechanisms of aminoglycoside resistance have developed in strains from specific geographical locations (with subsequent clonal spread), or whether common mechanisms have been acquired by genotypically distinct clinical isolates of Acinetobacter spp. throughout the world, a genotypically heterogeneous collection of 24 multiresistant clinical isolates of Acinetobacter spp. from 15 hospitals in 11 countries worldwide was studied. All were resistant to two or more aminoglycoside antibiotics. The full aminoglycoside resistance profile was determined for each isolate, allowing a putative enzyme content to be inferred, with subsequent confirmation of enzyme content and genetic location by polymerase chain reaction (PCR) and hybridisation techniques. All produced at least one aminoglycoside-modifying enzyme, most commonly AAC(3)-I and ANT(3'')-I in various combinations. Other enzymes found were AAC(3)-II, AAC(6')-I, ANT(2''), APH(3')-I and APH(3')-VI. None was confined to strains from a particular geographical area. Nine isolates transferred resistance mediated by AAC(3)-I, ANT(2'')-I, APH(3')-I or APH(3)'-VI by conjugation to a sensitive strain of A. baumannii, but most resistance was non-transferable. PCR mapping revealed an integron location in six isolates for the aac(3)-Ia gene and in three isolates for the ant(3'')-Ia gene. Overall, the study demonstrated that similar aminoglycoside-modifying enzymes are found in unrelated isolates of Acinetobacter spp., and that particular genes are not restricted to specific areas of the world. The demonstration of certain genes on plasmids and integrons emphasises the probable importance of these structures in the dissemination of certain types of aminoglycoside resistance in Acinetobacter spp.

Acinetobacter↗
PubMed1998

Characterization of In40 of Enterobacter aerogenes BM2688, a class 1 integron with two new gene cassettes, cmlA2 and qacF.

Enterobacter aerogenes BM2688, which is resistant to multiple antibiotics, and its aminoglycoside-susceptible derivative BM2688-1 were isolated from the same clinical sample. Strain BM2688 harbored plasmid pIP833, which carries a class 1 integron, In40, containing (in addition to qacEDelta1 and sul1, which are characteristic of class 1 integrons) four gene cassettes: aac(6')-Ib, qacF, cmlA2, and oxa-9. The cmlA2 gene had 83.7% identity with the previously described nonenzymatic chloramphenicol resistance cmlA1 gene. The qacF gene conferred resistance to quaternary ammonium compounds and displayed a high degree of similarity with qacE (67.8% identity) which, however, has been found as part of a cassette with a very different 59-base element. The oxa-9 gene was not expressed due to a lack of promoter sequences. Study of the antibiotic-susceptible derivative BM2688-1 indicated that a 3,148-bp deletion between the 3' end of the aac(6')-Ib gene and the 3' conserved segment of In40 was responsible for the loss of resistance. The occurrence of this DNA rearrangement, which did not involve homologous sequences, suggests that the In40 integrase could promote recombination at secondary sites.

Amino Acid Sequence↗
PubMed1998

Characterization of IS18, an element capable of activating the silent aac(6')-Ij gene of Acinetobacter sp. 13 strain BM2716 by transposition.

Insertion sequence IS18 was detected by analysis of the spontaneous aminoglycoside resistant mutant Acinetobacter sp. 13 strain BM2716-1. Insertion of the element upstream from the silent acetyltransferase gene aac(6')-Ij created a hybrid promoter that putatively accounts for the expression of the aminoglycoside resistance gene. The 1, 074-bp IS18 element contained partially matched (20 out of 26 bases) terminal inverted repeats, one of which overlapped the 3' end of a 935-bp open reading frame potentially encoding a protein related to the transposases of the IS30 family. IS18 was found in 6 out of 29 strains of Acinetobacter sp. 13 but not in 10 strains each of A. baumannii and A. haemolyticus.

Acinetobacter↗
PubMed1998

Neuroleptic management of schizophrenia: a survey and commentary on Australian psychiatric practice.

OBJECTIVE: We seek to assess Australian psychiatrists' views and practices concerning provision of neuroleptic medication to patients with schizophrenia, and to determine whether such management strategies are likely to have changed over time and the extent to which they correspond to published treatment guidelines. METHOD: A sample of 139 psychiatrists based in three Australian capital cities was derived, with respondents completing a brief questionnaire by choosing from a limited-option answer set. Co-authors of this paper comment on the extent to which responses are in line with contemporary recommendations driven by experts or empirical studies. RESULTS: Overall, survey findings indicate that there has been considerable change in clinical practice over the last decade and provide some estimate of the extent to which Australian management practices are congruent with contemporary recommendations. We identify a number of issues of concern (more in relation to dose levels of neuroleptic medication rather than treatment duration) revealed by survey data and make recommendations for addressing a number of practical clinical issues. CONCLUSIONS: As this report focuses on central issues involved in managing schizophrenia, and integrates a number of treatment guidelines, we suggest that it should be of assistance for practice review by clinicians.

Antipsychotic Agents↗
PubMed1998

Dysmorphic concern: prevalence and associations with clinical variables.

OBJECTIVE: The aim of this paper is to describe the development of a questionnaire, the Dysmorphic Concern Questionnaire (DCQ), for the assessment of dysmorphic concern, and to establish correlations with clinical variables. METHOD: Consecutive admissions to a psychiatric hospital were surveyed. RESULTS: The DCQ showed good internal consistency, with most of the variance being explained by a single factor. Strong correlations with distress and work and social impairment lend face validity to the questionnaire. Dysmorphic concern was not significantly influenced by the patient's age, sex or diagnosis. In terms of specific psychotic symptoms, there were weak positive correlations with thought interference and persecutory ideation. However, the strongest correlations were with depressed mood, according to the Beck Depression Inventory (BDI) but not the Montgomery Asberg Depression Rating Scale; the discrepancy was largely accounted for by the 'cognitive' depressive items on the BDI. In terms of objective assessment of dysmorphic features, ratings on the Waldrop scale for minor physical anomalies showed no correlation with concern expressed by the patient. CONCLUSIONS: The strong correlation with depressive cognitions suggests that dysmorphic concern is often a reflection of a depressive cognitive set rather than being a diagnosis in itself.

Adult↗
PubMed1997

Portal vein complications after liver transplantation for biliary atresia.

The objective of this report is to review portal complications (PC) after pediatric liver transplantation (LT) for biliary atresia (BA) in the Bicêtre surgical series. From January 1, 1988, to February 28, 1995, 96 children with BA underwent 115 LTs Portal anastomosis was done on either the recipient portal vein (n = 85) or superior mesenteric vein (n = 11). No antiaggregative agents were administered postoperatively. Median follow-up was 50 months (range, 12 to 97). Nineteen PC (16.5%) occurred in 17 recipients: 16 portal thrombosis (PT) and 3 portal stenosis (PS). Fifteen instances of early PT occurred between days 0 and 17 (median, day 2). Emergency thrombectomy was performed in 9 cases (successful in 5). Three children underwent a secondary portosystemic shunt (successful in 2). Three PS were cured by either surgery or balloon dilatation. Four children died, 3 are alive with portal hypertension (PHT), and 10 are alive without PHT. Three-year patient actuarial survival is 82.4% in PC cases and 82% in others (NS). Significant risk factors of PC are young age and weight at the time of LT, small portal vein, and emergency LT. Analysis of our own results and review of the literature suggest that prevention of PC depends primarily on appropriate surgical technique. Reduction of postoperative hypercoagulability may also play an important role: a meta-analysis of 1,257 published pediatric LT show an overall risk of PT of 2.2% in teams using aspirin with or without dipyridamole compared with 7.8% when no antiaggregative agents are given (P = .0001).

Adolescent↗
PubMed1997

Loss of intrinsic aminoglycoside resistance in Acinetobacter haemolyticus as a result of three distinct types of alterations in the aac(6')-Ig gene, including insertion of IS17.

The distribution of the aac(6')-Ig gene, encoding aminoglycoside 6'-N-acetyltransferase-Ig [AAC(6')-Ig], was studied in 96 Acinetobacter haemolyticus strains and 12 proteolytic Acinetobacter strains, including Acinetobacter genomospecies 6, 13, and 14 and 3 unnamed species assigned to this genomic group by DNA-DNA hybridization. This gene was detected by DNA-DNA hybridization in all 96 A. haemolyticus strains and by PCR in 95 strains but was not detected in strains of other species, indicating that it may be used to identify A. haemolyticus. Three A. haemolyticus strains were susceptible to tobramycin and did not produce an aminoglycoside 6'-N-acetylating activity, although they contained aac(6')-Ig-related sequences. An analysis of three susceptible A. haemolyticus strains indicated that aminoglycoside resistance was abolished by the following three distinct mechanisms: (i) a point mutation in aac(6')-Ig that led to a Met56-->Arg substitution, which was shown by analysis of a revertant to be responsible for the loss of resistance; (ii) a polythymine insertion that altered the reading frame; and (iii) insertion of IS17, a new member of the IS903 family. These observations indicated that AAC(6')-Ig is not essential for the viability of A. haemolyticus, although the aac(6')-Ig gene was detected in all members of this species.

Acetyltransferases↗