Prevalence of tetracycline resistance genes in oral bacteria

Tetracycline is a broad-spectrum antibiotic used in humans, animals, and aquaculture; therefore, many bacteria from different ecosystems are exposed to this antibiotic. In order to determine the genetic basis for resistance to tetracycline in bacteria from the oral cavity, saliva and dental plaque samples were obtained from 20 healthy adults who had not taken antibiotics during the previous 3 months. The samples were screened for the presence of bacteria resistant to tetracycline, and the tetracycline resistance genes in these isolates were identified by multiplex PCR and DNA sequencing. Tetracycline-resistant bacteria constituted an average of 11% of the total cultivable oral microflora. A representative 105 tetracycline-resistant isolates from the 20 samples were investigated; most of the isolates carried tetracycline resistance genes encoding a ribosomal protection protein. The most common tet gene identified was tet(M), which was found in 79% of all the isolates. The second most common gene identified was tet(W), which was found in 21% of all the isolates, followed by tet(O) and tet(Q) (10.5 and 9.5% of the isolates, respectively) and then tet(S) (2.8% of the isolates). Tetracycline resistance genes encoding an efflux protein were detected in 4.8% of all the tetracycline-resistant isolates; 2.8% of the isolates had tet(L) and 1% carried tet(A) and tet(K) each. The results have shown that a variety of tetracycline resistance genes are present in the oral microflora of healthy adults. This is the first report of tet(W) in oral bacteria and the first report to show that tet(O), tet(Q), tet(A), and tet(S) can be found in some oral species.

Recent advances in the design and performance of research assistants

Every laboratory needs personnel who work 24 hours a day 7 days a week, are efficient, obedient, capable of showing initiative, insightful and affable. Our experience of laboratory workers tells us that there is an immense way to go to achieve these goals. Having tired of the normal, Darwinian approach, a project has been initiated to achieve these ends through genetic technologies.

A preliminary trial of high-dose ursodeoxycholic acid in primary sclerosing cholangitis

BACKGROUND & AIMS

Ursodeoxycholic acid (UDCA) is used for the treatment of cholestatic liver diseases including primary biliary cirrhosis (PBC) for which it has a positive effect on laboratory values, may delay the development of liver failure and prolong the transplant-free disease period. Standard doses of UDCA (8-15 mg/kg daily) have been shown to be ineffective in the treatment of primary sclerosing cholangitis (PSC). We report on the findings (clinical, biochemical, histological, and cholangiographic) and side effects of a 2-year double-blind placebo-controlled preliminary study of high-dose UDCA in PSC patients.

METHODS

Twenty-six patients with PSC were randomized to high-dose (20 mg/kg daily) UDCA or placebo. Cholangiography and liver biopsy were performed at entry and after 2 years. Symptoms, clinical signs, and liver biochemical tests were recorded at 3 monthly intervals.

RESULTS

High-dose UDCA did not influence symptoms, but there was a significant improvement in liver biochemistry (serum alkaline phosphatase, P = 0.03; gamma-glutamyl transferase, P = 0.01) and a significant reduction in progression in cholangiographic appearances (P = 0.015) and liver fibrosis as assessed by disease staging (P = 0.05). In the treatment group, a significant increase in total bile acids and saturation with UDCA >70% confirmed patient compliance. No significant side effects were reported.

CONCLUSIONS

High-dose UDCA may be of clinical benefit in PSC, but trials with a larger number of participants and of longer duration are required to establish whether the effect of high-dose UDCA on liver biochemistry, histology, and cholangiography in patients with PSC is translated into improved long-term survival.

Incidence, natural history and risk factors of deep vein thrombosis in elective knee arthroscopy

AIMS

to determine the incidence, anatomical distribution and extent of deep vein thrombosis (DVT) in limbs undergoing elective unilateral knee arthroscopy without active prophylaxis, to evaluate its effect on venous function following early diagnosis, and to quantify the impact of risk factors on its incidence.

METHODS

102 consecutive patients undergoing unilateral knee arthroscopy without prophylaxis were studied. A history was obtained with emphasis on the risk factors for thromboembolism, and physical examination and colour duplex were performed prior to and within a week after surgery. Patients who developed calf DVT were given aspirin (150 mg) and compression stockings; those with proximal DVT were admitted for anticoagulation (heparin followed by warfarin). Follow-up (mean 118 [range 84-168] days) entailed weekly physical and duplex examinations during the first month and monthly thereafter.

RESULTS

8 patients developed calf DVT in the operated leg (incidence 7.84% [95% CI: 2.7%-13.2%]); thrombosis was asymptomatic in 4 of those (50%), caused calf tenderness in 4 (50%) and a positive Homan's sign in one (12.5%). DVT occurred in the following veins: peroneal 4 subjects (50%), soleal 4 (50%), gastrocnemial 2 (25%) and tibial 2 (25%). Propagation of a calf DVT to the popliteal vein was identified in 1 patient (12.5%). After a median period of 118 days, total clot lysis was found in 50% of DVTs. with partial thrombus resorption in the rest; reflux in the thrombosed veins was present in 75% of limbs with DVT. 43% of patients had 1 risk factor for DVT and 20% had > or = 2. The incidence of DVT was higher amongst those with two or more risk factors for thromboembolism (p <.05) or those with previous thrombosis alone (p <.005). Symptoms or signs of pulmonary embolism were not documented.

CONCLUSIONS

Elective unilateral knee arthroscopy performed without prophylaxis is complicated by ipsilateral calf DVT in 7.8% (95% CI: 2.7%-13.2%) of cases. The risk is higher in the presence of previous thrombosis (relative risk: 8.2) and two or more risk factors for DVT (relative risk: 2.94). Thrombosis may propagate to the proximal veins, despite early diagnosis. 50% of calf clots totally lyse in 4 months, yet reflux develops in at least 75% of limbs with DVT. Further studies to determine optimal prophylaxis are warranted.

Chondral lesions of the knee: A new localization method and correlation with associated pathology

PURPOSE

We report a new method of describing and recording chondral lesions of the knee at arthroscopy in order to permit a more accurate and meaningful analysis of patterns of articular cartilage damage.

TYPE OF STUDY

Case series study.

METHODS

Data were collected prospectively at 1,000 consecutive arthroscopies by the senior author and chondral lesions were recorded on anatomic articular maps divided into different functional zones. Ten zones on the femur were determined by tibiofemoral weight-bearing and flexion horizons (namely the 0 degrees, 45 degrees, 90 degrees, and 120 degrees horizons as they pass the anterior meniscosynovial junction). Ten zones were determined on the tibia, principally by meniscal relations, and 6 zones on the patella. This allowed the size, Outerbridge grade, and location to be analyzed in relation to mechanism, chronicity, and associated intra-articular pathologies. The recording methods were tested for interobserver reproducibility in 50 subsequent cases at the same arthroscopy by 2 independent observers. The results were analyzed by a third person, and showed a relatively small interobserver error of 7.2% for size for a set of grade 3 and 4 lesions and only a 3% error for site. The Fisher exact test was used. The data sheets were entered onto a computer spreadsheet database using standard software (Excel; Microsoft, Redmond, WA) to permit analysis of the data.

RESULTS

There were 1,553 chondral lesions in 853 patients correlated with associated lesions, including 356 meniscal lesions, 230 ligamentous injuries, 440 synovial lesions, and other pathologies. High degrees of correlation have been found between specific lesions and their opposing surfaces and the progression of these with time.

CONCLUSIONS

The problem of precision of localization of articular lesions in the knee has been recently acknowledged by the International Cartilage Research Society (ICRS). However, such recording ought to take into account both function and contact with other structures. This would appear essential in the assessment of prognosis and comparisons between different treatment regimes.

The long-term consequences of war: the experience of World War II

Seven hundred and thirty-one World War II and Korean War veterans completed a questionnaire about their experiences and their current psychological reactions to the war. Nineteen percent scored above the cut-off points for both the General Health Questionnaire and the (war-related) Impact of Event Scale, demonstrating that, even over 50 years after the event, many veterans still experience problems relating to their war experiences. Psychological distress was in part directly related to particular experiences, but intrusion and avoidance both played an important role as mediating variables. Other factors, such as prisoner of war (POW) status, type of service, rank, and illness were also considered. The findings indicate that the effects of a traumatic experience such as war can persist into later life.

World war II veterans, social support, and veterans' associations

People use many different coping strategies to deal with their traumatic recollections. Twenty-five British World War II veterans were interviewed regarding the ways they used social support both during the war and in the years afterwards. The findings demonstrate that social support is used in fundamentally different ways. During the war comradeship was particularly important and even fifty years after the war comrades are still a valuable resource for discussing war experiences, and dealing with the emotional content of traumatic recollections. Veterans rely on wives and families to help deal with the more physical and practical elements of coping, but tend not to discuss their traumatic memories with them. The findings show that social support is an important lifelong coping strategy for World War II veterans.

Faster introduction of cost-effective packaging films

The introduction of more cost-effective packaging is restricted by the lack of resources and time that is available for validating new materials. New techniques are being developed to shorten approval times and reduce hold-ups in benefitting from innovative packaging solutions.

A confirmatory factor analysis of the Impact of Event Scale using a sample of World War II and Korean War veterans

This study assessed the factor structure of the Impact of Event Scale (IES), a measure of intrusion and avoidance, using a sample of World War II and Korean War veterans who had experienced combat 40-50 years earlier. A series of 3 confirmatory factor analytic models were specified and estimated using LISREL 8.3. Model 1 specified a 1-factor model. Model 2 specified a correlated 2-factor model. Model 3 specified a 2-factor model with additional cross-factor loadings for Items 2 and 12. Model 3 was found to fit the data. In addition, this model was found to be a better explanation of the data than the other models. Also in addition, the correlations between the Intrusion and Avoidance factors and the 4 subscales of the 28-item General Health Questionnaire were examined to determine the distinctiveness of the two IES factors.

cis-Active elements of Friend spleen focus-forming virus: from disease induction to disease prevention

The polycythemic strain of the Friend spleen focus-forming virus (SFFVp) is a replication-defective, acutely transforming retrovirus inducing a bistage erythroleukemia in susceptible mice. The first stage of the disease is an acute polyclonal erythroblastosis induced by the proliferation-promoting effect of gp55. gp55 is expressed from a spliced subgenomic message of SFFVp and stimulates the cellular receptor for erythropoietin. Using a selectable SFFVp that otherwise mimics the specificity of the disease, we demonstrate that the kinetics of the polyclonal expansion depends on the transcriptional strength of the retroviral cis-active elements. By exchanging gp55 for apathogenic genes, we show that SFFVp enhancer and splice signals can be successfully utilized for the development of retroviral vectors mediating very efficient transgene expression in hematopoietic cells. Apathogenic selectable SFFVp-based vectors carrying distinct enhancer alterations are a valuable tool to analyze transcriptional control of leukemia viruses in the absence of oncogenic proteins. Moreover they might have therapeutic potential.

Oligonucleotide microarray based detection of repetitive sequence changes

Prior studies of oligonucleotide microarray-based mutational analysis have demonstrated excellent sensitivity and specificity except in circumstances where a frameshift mutation occurs in the context of a short repeated sequence. To further evaluate this circumstance, a series of nucleic acid samples having heterozygous mutations within repetitive BRCA1 sequence tracts was prepared and evaluated. These mutations included single nucleotide insertions and deletions in homopolymer runs, insertions and deletions of trinucleotide repeats, and duplications. Two-color comparative hybridization experiments were used wherein wild type reference and test targets are co-hybridized to microarrays designed to screen the entire BRCA1 coding sequence for all possible sequence changes. Mutations in simulated heterozygote samples were detected by observing relative losses of test target hybridization signal to select perfect match oligonucleotide probes. While heterozygous mutations could be readily distinguished above background noise in 9/19 cases, it was not possible to detect alterations in a poly dA/dT tract, small triplet repeat expansions, and a 10 bp direct repeat. Unexpectedly, samples containing (GAT)(3) triplet repeat expansions showed significantly higher affinity toward specific perfect match probes relative to their wild type counterparts. Therefore, markedly increased as well as decreased test sample hybridization to perfect match probes should be used to raise a suspicion of repetitive sequence changes.

Improvement in function after valgus bracing of the knee

The use of a valgus brace can effectively relieve the symptoms of unicompartmental osteoarthritis of the knee. This study provides an objective measurement of function by analysis of gait symmetry. This was measured in 30 patients on four separate occasions: immediately before and after initial fitting and then again at three months with the brace on and off. All patients reported immediate symptomatic improvement with less pain on walking. After fitting the brace, symmetry indices of stance and the swing phase of gait showed a consistent and immediate improvement at 0 and 3 months, respectively, of 3.92% (p = 0.030) and 3.40% (p = 0.025) in the stance phase and 11.78% (p = 0.020) and 9.58% (p = 0.005) in the swing phase. This was confirmed by a significant improvement at three months in the mean Hospital for Special Surgery (HSS) knee score from 69.9 to 82.0 (p < 0.001). Thus, wearing a valgus brace gives a significant and immediate improvement in the function of patients with unicompartmental osteoarthritis of the knee, as measured by analysis of gait symmetry.

Improvement in function after valgus bracing of the knee. An analysis of gait symmetry

The use of a valgus brace can effectively relieve the symptoms of unicompartmental osteoarthritis of the knee. This study provides an objective measurement of function by analysis of gait symmetry. This was measured in 30 patients on four separate occasions: immediately before and after initial fitting and then again at three months with the brace on and off. All patients reported immediate symptomatic improvement with less pain on walking. After fitting the brace, symmetry indices of stance and the swing phase of gait showed a consistent and immediate improvement at 0 and 3 months, respectively, of 3.92% (p = 0.030) and 3.40% (p = 0.025) in the stance phase and 11.78% (p = 0.020) and 9.58% (p = 0.005) in the swing phase. This was confirmed by a significant improvement at three months in the mean Hospital for Special Surgery (HSS) knee score from 69.9 to 82.0 (p < 0.001). Thus, wearing a valgus brace gives a significant and immediate improvement in the function of patients with unicompartmental osteoarthritis of the knee, as measured by analysis of gait symmetry.

Inhibition of in vitro lymphoproliferation by three novel iron chelators of the pyridoxal and salicyl aldehyde hydrazone classes

The capacity of three novel iron chelators, namely 1-[N-ethoxycarbonylmethylpyridoxylidenium]-2-[2'-pyridyl]hydrazine bromide (EPH), 1-[5'-bromosalicylidene]-2-[2"-pyridyl]hydrazine (BsPH), and 1-pyridoxylidene-2-[1'-phthalazyl]hydrazine dihydrochloride (PPhH), to inhibit the proliferation of mitogen-stimulated murine lymph node cells was examined in vitro. All three are of the aryl hydrazone class, the prototype of which is pyridoxal isonicotinoyl hydrazone. The chelators inhibited lymphoproliferation at low micromolar concentrations. EPH and PPhH had an inhibitory capacity comparable to that of desferrioxamine (IC(50): 3 and 2 microM, respectively), whereas BsPH was more potent (IC(50) < 1 microM). The inhibitory effects of the chelator were not due to cell cytotoxicity and could be abrogated by pretreating the chelator with iron. Time-course studies established a site of action for the chelators at the G(1)/S phase transition. These agents warrant further investigation for their potential as immunosuppressants.

Temporal patterning of competitive emotions: a critical review

An interactional model of stress that integrates current research on competitive affects and emphasizes the temporal dimensions of the stress process is forwarded. The literature reveals that the study of athletes' affective responses to competition has been narrowly focused on pre-competitive anxiety. Equivocal findings on temporal patterning of competitive anxiety suggest that a fundamental change in the empirical approach is needed because the current conceptualization of anxiety and other complex emotions is imprecise. The analysis of secondary emotions as patterns of discrete basic emotions, as suggested by differential emotions theorists, is proposed for consideration in future research. In this view, competitive anxiety is considered as a set of patterns of emotions rather than a unitary affect. The adoption of this approach could result in better operationalization of competitive anxiety as well as other secondary performance-related emotions. We propose that research on competitive affects should follow two parallel lines. The first should focus on the description of complex emotional states that reflect the idiosyncratic emotional experience and vocabulary of the athlete. The second should examine the sets of basic emotions experienced throughout competition, and focus on individual differences and factors determining those differences. The integration of the two approaches could lead to a better understanding of whether, how and why individuals differ in the interpretation of specific secondary emotions and their effect on performance. Moreover, it would permit the analysis of intra-individual variations in labelling secondary emotions with respect to different competitive contexts and temporal aspects.

Superlattice formation in mixtures of hard-sphere colloids

We report a detailed experimental study of the superlattice structures formed in dense binary mixtures of hard-sphere colloids. The phase diagrams observed depend sensitively on the ratio alpha=R(S)/R(L) of the radii of the small (S) and large (L) components. Mixtures of size ratio alpha=0.72, 0.52, 0.42, and 0.39 are studied. The structures of the colloidal phases formed were identified using a combination of light-scattering techniques and confocal fluorescent microscopy. At alpha=0.39, ordered binary crystals are formed in suspensions containing an equal number of large and small spheres which microscopy shows have a three-dimensional structure similar to either NaCl or NiAs. At the larger size ratio, alpha=0.52, we observe LS2 and LS13 superlattices, isostructural to the molecular compounds AlB2 and NaZn13, while at alpha=0.72 the two components are immiscible in the solid state and no superlattice structures are found. These experimental observations are compared with the predictions of Monte Carlo simulations and cell model theories.

The development of a tactile graphic version of IOTN for visually impaired patients

The Index of Orthodontic Treatment Need (IOTN) is a visual-based index and has been widely used. This paper describes the development and evaluation of tactile graphics representing the aesthetic component (AC) of IOTN for the use of visually impaired patients (VI). Four tactile graphics were produced corresponding to IOTN photographs 1 (graphic 1, no treatment - mild need), 5 (graphic 2, moderate need), 8 (graphic 3, severe need; increased overjet) and 10 (graphic 4, severe need). Nine (30-50 years) expert consumers from the Royal National Institute for the Blind (RNIB) and 13 VI schoolchildren (11-16 years) evaluated the graphics. The evaluation was in terms of design features, complexity of information and ease of use. Each individual was asked to arrange the graphics in order of severity of malocclusion. The procedure was repeated after 30 min to test individual reliability (http://www.clinorthodres.com/cor-c-084/). The consumer group was able to identify the main features in each graphic and found them easy to use. Six had arranged the graphics correctly at the first attempt and five on their second. The children were able to distinguish the different oral features, except the overjet presentation in graphic 2. Nine children arranged the graphics correctly at the first attempt, but only six at the second. The confusion centred for both groups on presenting an increased overjet with graphic 2. A modification was undertaken to enhance the anterior-posterior nature of the image. Fifteen VI schoolchildren reassessed the modified graphics, 14 arranged them correctly at the first attempt and 13 at the second. The study concluded that IOTN tactile graphics were well accepted and showed a good reliability.

Cloning and expression analysis of testis-specific cyclic 3', 5'-adenosine monophosphate-responsive element modulator activators in the nonhuman primate (Macaca fascicularis): comparison with other primate and rodent species

The cAMP-responsive element modulator (CREM) gene encodes a transcription factor that is essential for spermatogenesis. In mouse testis, several CREM repressors and activators have been identified. In contrast to the situation for the mouse, however, little is known about CREM isoforms in the primate testis. We analyzed CREM isoforms and mRNA expression in a clinically relevant primate model, the cynomolgus monkey (Macaca fascicularis). A cDNA library was generated from monkey testis; and two activator isoforms (tau2 with and without exon gamma) were identified, which displayed high sequence identity to mouse and human isoforms. The insertion of exon gamma was observed for the first time in the primate testis. CREM activator expression was confined to the testis, where it was seen in late pachytene spermatocytes and round spermatids in specific spermatogenic stages, as revealed by in situ hybridization. Comparison of the mRNA and the recently described protein expression indicated a lack of translational delay of CREM expression. Comparative analysis of testicular CREM expression by reverse transcription-polymerase chain reaction yielded several transcripts in the rat, mouse, hamster, and marmoset; two transcripts in cynomolgus and rhesus monkeys; and one transcript in men. These findings suggest an evolutionary trend from multiple activator isoforms to a single activator transcript in men.

The development of a tactile graphic version of IOTN for visually impaired patients

The Index of Orthodontic Treatment Need (IOTN) is a visual-based index and has been widely used. This paper describes the development and evaluation of tactile graphics representing the aesthetic component (AC) of IOTN for the use of visually impaired patients (VI). Four tactile graphics were produced corresponding to IOTN photographs 1 (graphic 1, no treatment - mild need), 5 (graphic 2, moderate need), 8 (graphic 3, severe need; increased overjet) and 10 (graphic 4, severe need). Nine (30-50 years) expert consumers from the Royal National Institute for the Blind (RNIB) and 13 VI schoolchildren (11-16 years) evaluated the graphics. The evaluation was in terms of design features, complexity of information and ease of use. Each individual was asked to arrange the graphics in order of severity of malocclusion. The procedure was repeated after 30 min to test individual reliability (www.clinorthodres.com/cor-c-084/). The consumer group was able to identify the main features in each graphic and found them easy to use. Six had arranged the graphics correctly at the first attempt and five on their second. The children were able to distinguish the different oral features, except the overjet presentation in graphic 2. Nine children arranged the graphics correctly at the first attempt, but only six at the second. The confusion centred for both groups on presenting an increased overjet with graphic 2. A modification was undertaken to enhance the anterior-posterior nature of the image. Fifteen VI schoolchildren reassessed the modified graphics, 14 arranged them correctly at the first attempt and 13 at the second. The study concluded that IOTN tactile graphics were well accepted and showed a good reliability.

Drug information systems, early warning, and new drug trends: can drug monitoring systems become more sensitive to emerging trends in drug consumption?

Drug Information Systems (DIS) are called upon to provide an early warning of emerging trends in drug use. However, little theoretical attention is directed toward exploring conceptual issues in this area. In this paper a typology of existing DIS is offered. Among the features that distinguish DIS are their structure (human network or organization systems) and the range of information sources used. Indicators of drug use can be placed on a continuum of sensitivity ranging from leading edge indicators to lagged indicators. Sensitivity implies volatility as sensitive indicators also react to fluctuations that do not become trends. DIS conventionally are largely reliant upon lagged indicators. What is required are DIS that combine a critical information processing function with the ongoing systematic collection of data from a range of data sources.