B-cell lymphoma in the peripheral nerves of a cat

A B-cell, Burkitt-type lymphoma, diffusely affecting the peripheral nerves and intramuscular nerve branches was diagnosed in a 4-year-old domestic shorthair cat with a chronic progressive history of flaccid tetraparesis and generalized muscle atrophy. There was no evidence of cranial nerve, central nervous system, radicular, bone marrow, splenic, or lymph node involvement. The cat tested negative for feline retroviruses and a wide variety of herpes viruses, including Epstein-Barr virus. The clinical manifestation of this case was similar to the chronic polyneuropathic variant of human diffuse neurolymphomatosis; a condition most commonly caused by an axonopathy resulting from infiltration of peripheral nerves with non-Hodgkin's lymphoma.

Quantitative objective markers for upper and lower motor neuron dysfunction in ALS

OBJECTIVE

To investigate the value of objective biomarkers for upper (UMN) and lower (LMN) motor neuron involvement in ALS.

METHODS

We prospectively studied 64 patients with ALS and its subsets using clinical measures, proton MR spectroscopic imaging ((1)H MRSI), diffusion tensor imaging, transcranial magnetic stimulation, and the motor unit number estimation (MUNE) at baseline and every 3 months for 15 months and compared them with control subjects.

RESULTS

(1)H MRSI measures of the primary motor cortex N-acetyl-aspartate (NAA) concentration were markedly reduced in ALS (p = 0.009) and all UMN syndromes combined (ALS, familial ALS [fALS], and primary lateral sclerosis; p = 0.03) vs control values. Central motor conduction time to the tibialis anterior was prolonged in ALS (p < 0.0005) and combined UMN syndromes (p = 0.001). MUNE was lower in ALS (p < 0.0005) and all LMN syndromes combined (ALS, fALS, and progressive muscular atrophy; p = 0.001) vs controls. All objective markers correlated well with the ALS Functional Rating Scale-Revised, finger and foot tapping, and strength testing, suggesting these markers related to disease activity. Regarding changes over time, MUNE changed rapidly, whereas neuroimaging markers changed more slowly and did not significantly differ from baseline.

CONCLUSIONS

(1)H MR spectroscopic imaging measures of the primary motor cortex N-acetyl-aspartate (NAA) concentration and ratio of NAA to creatine, central motor conduction time to the tibialis anterior, and motor unit number estimation significantly differed between ALS, its subsets, and control subjects, suggesting they have potential to provide insight into the pathobiology of these disorders.

Tuberculosis outbreak linked to pubs in south Wales

On 10 February 2004, the specialist respiratory nurse for a hospital in a city in South Wales alerted the local health authorities that Mycobacterium tuberculosis infections

Measuring sub-bandage pressure: comparing the use of pressure monitors and pulse oximeters

OBJECTIVE

To test the use of low-cost sub-bandage pressure monitors and pulse oximeters as part of a quality-control measure for graduated compression bandaging in leg ulcer clinics.

METHOD

Twenty-five healthy volunteers (mean age 40 years) providing 50 limbs were bandaged with a four-layer compression bandaging system. The ankle systolic pressure (ASP) was measured using a pulse oximeter (Nellcor NBP-40) before applying the graduated compression bandages. Interface pressure was measured by placing pressure sensors on the skin at three points (2cm above the medial malleolus; the widest part of the calf; and a point midway between them) in the supine and standing positions. The ASP was measured again with the pulse oximeter after the bandage had been applied, and the effect of the bandage on the ASP was recorded. The actual pressure created by the bandage was compared with the required pressure profile.

RESULTS

Interface pressures varied with change of position and movement. With the operator blinded to the pressure monitors while applying the bandages, the target pressure of 35-40mmHg at the ankle was achieved in only 36% of limbs ([mean +/- 95% confidence interval]; 32.3 +/- 1.6mmHg [supine]; 38.4 +/- 2.4mmHg [standing position]). With the help of the pressure monitors, the target pressure was achieved in 78% of the limbs. There was no correlation between the pressure monitors and pulse oximeter pressures, demonstrating that the pulse oximeter is not a useful tool for measuring sub-bandage pressures.

CONCLUSION

The results suggest a tool (interface pressure monitors) that is easy to operate should be available as part of quality assurance for treatment, training of care providers and education.

Molecular Characterization, Phylogenetic Relationships, and Specific Detection of Peach mosaic virus

ABSTRACT Peach mosaic virus (PcMV) and Cherry mottle leaf virus (CMLV) are serologically related viruses that cause distinct diseases, have a different host range, and are vectored by different eriophyid mites. Sequence analysis of the genome of PcMV indicates that it is closely related genetically to CMLV but distinct, with similar genome organization and a member of the genus Trichovirus. The genome of PcMV consists of 7,988 nucleotides, excluding a poly(A) tail at the 3' end of the genome. Four putative open reading frames (ORF1 to 4) were identified coding for proteins of 216.3, 47.2, 21.7, and 15.7 kDa, respectively. Also, three noncoding regions were identified, including an intergenic region separating ORF3 and ORF4. The complete nucleotide sequence of PcMV shares 73% identity with CMLV. The CP amino acid sequence identity between isolates of PcMV ranged from 97 to 99% versus 83% identity when compared with the CP of CMLV. In vitro expression and subsequent western blot analysis confirmed ORF3 as encoding the CP gene of PcMV. Phylogenetic analysis supports classification of PcMV and CMLV as members of the genus Trichovirus. They are unique members of this genus with an extra ORF (ORF4). PcMV ORF4 appears to code for a putative nucleic acid-binding (NB) protein which has identity with the NB protein of CMLV and members of the genera Allexivirus, Carlavirus, and Vitivirus. PcMV and CMLV appear to be the products of recombination between members of the genus Trichovirus and a virus group containing the putative NB protein. Alternatively, PcMV and CMLV may represent the intact genome, with a deletion event producing members that lack ORF4. A reverse transcription-polymerase chain reaction procedure was developed for reliable and specific detection of PcMV. This will be an asset for stone fruit virus certification.

Forensic facial approximation: an overview of current methods used at the Victorian Institute of Forensic Medicine/Victoria Police Criminal Identification Squad

Forensic facial approximation involves building a likeness of the head and face on the skull of an unidentified individual, with the aim that public broadcast of the likeness will trigger recognition in those who knew the person in life. This paper presents an overview of the collaborative practice between Ronn Taylor (Forensic Sculptor to the Victorian Institute of Forensic Medicine) and Detective Sergeant Adrian Paterson (Victoria Police Criminal Identification Squad). This collaboration involves clay modelling to determine an approximation of the person's head shape and feature location, with surface texture and more speculative elements being rendered digitally onto an image of the model. The advantages of this approach are that through clay modelling anatomical contouring is present, digital enhancement resolves some of the problems of visual perception of a representation, such as edge and shape determination, and the approximation can be easily modified as and when new information is received.

The effect of dietary fish oil supplementation on exercising horses

Ten horses of Thoroughbred or Standardbred breeding were used to study the effects of dietary fish oil supplementation on the metabolic response to a high-intensity incremental exercise test. Horses were assigned to either a fish oil (n = 6) or corn oil (n = 4) treatment. The fish oil (Omega Protein, Hammond, LA) contained 10.6% eicosapentaenoic acid and 8% docosahexaenoic acid. Each horse received timothy hay and a textured concentrate at a rate necessary to meet its energy needs. The supplemental oil was top-dressed on the concentrate daily at a rate of 324 mg/kg BW. Horses received their assigned diet for 63 d, during which time they were exercised 5 d/wk in a round pen or on a treadmill. During wk 1, horses exercised for 10 min at a trot. After wk 1, exercise time and intensity were increased so that at wk 5, exercise time in the round pen increased to 30 min (10 min of cantering and 20 min of trotting) per day. Starting at wk 6, horses were exercised 3 d/wk in the round pen for 30 min and 2 d/wk on a treadmill for 20 min. After 63 d, all horses performed an exercise test consisting of a 5-min warm-up at 1.9 m/s, 0% grade, followed by a step test on a 10% grade at incremental speeds of 2 to 8 m/s. Blood samples were taken throughout exercise. During exercise, horses receiving fish oil had a lower heart rate (treatment x time interaction; P < 0.05) and tended to have lower packed cell volume (treatment effect; P = 0.087). Plasma lactate concentrations were not affected by treatment. Plasma glucose concentrations were not different between groups during exercise but were lower (treatment x time interaction; P < 0.01) for the fish oil group during recovery. Serum insulin tended to be lower in fish oil horses throughout exercise (treatment effect; P = 0.064). There was a tendency for glucose:insulin ratios to be higher for fish oil-treated horses throughout exercise (treatment effect; P = 0.065). Plasma FFA were lower (treatment x time interaction; P < 0.01) in horses receiving fish oil than in horses receiving corn oil during the initial stages of the exercise test. Serum glycerol concentrations also were lower in fish oil-treated horses (P < 0.05). Serum cholesterol concentrations were lower in horses receiving fish oil (treatment effect; P < 0.05), but serum triglycerides were not affected by treatment (P = 0.55). These data suggest that addition of fish oil to the diet alters exercise metabolism in conditioned horses.

Quality of life changes following peripheral blood stem cell transplantation and participation in a mixed-type, moderate-intensity, exercise program

The purpose of this investigation was to evaluate the impact of undertaking peripheral blood stem cell transplantation (PBST) on quality of life (QoL), and to determine the effect of participating in a mixed-type, moderate-intensity exercise program on QoL. It was also an objective to determine the relationship between peak aerobic capacity and QoL in PBST patients. QoL was assessed via the CARES questionnaire and peak aerobic capacity by a maximal graded treadmill test, pretransplant (PI), post transplant (PII) and following a 12-week intervention period (PIII). At PII, 12 patients were divided equally into a control or exercise intervention group. Undergoing a PBST was associated with a statistically but not clinically significant decline in QoL (P<0.05). Following the intervention, exercising patients demonstrated an improved QoL when compared with pretransplant ratings (P<0.01) and nonexercising transplant patients (P<0.05). Moreover, peak aerobic capacity and QoL were correlated (P<0.05). The findings demonstrated that exercise participation following oncology treatment is associated with a reduction in the number and severity of endorsed problems, which in turn leads to improvements in global, physical and psychosocial QoL. Furthermore, a relationship between fitness and QoL exists, with those experiencing higher levels of fitness also demonstrating higher QoL.

Contextual Assessment of the Maternity Experience: development of an instrument for cross-cultural research

BACKGROUND

There is evidence that stressors may trigger the onset of a depressive episode in vulnerable women. A new UK interview measure, the Contextual Assessment of the Maternity Experience (CAME), was designed to assess major risk factors for emotional disturbances, especially depression, during pregnancy and post-partum.

AIMS

With in the context of a cross-cultural study, to establish the usefulness of the CAME, and to test expected associations of the measure with characteristics of the social context and with major or minor depression.

METHOD

The CAME was administered antenatally and postnatally in ten study sites, respectively to 296 and 249 women. Affective disorder throughout pregnancy and up to 6 months postnatally was assessed by means of the Structured Clinical Interview for DSM-IVAxis I Disorders.

RESULTS

Adversity, poor relationship with either a partner or a confidant, and negative feelings about the pregnancy all predicted onset of depression during the perinatal period.

CONCLUSIONS

The CAME was able to assess major domains relevant to the psychosocial context of the maternity experience in different cultures. Overall, the instrument showed acceptable psychometric properties in its first use in different cultural settings.

Detection of a New and Unusual Isolate of Plum pox virus in Plum (Prunus domestica)

Plum pox virus (PPV) isolate 3174-01 was detected by triple-antibody sandwich enzyme-linked immunosorbent assay using the universal PPV monoclonal antibody (MAb) 5B as the secondary antibody, and by reverse-transcription polymerase chain reaction (RT-PCR) using primers that amplify a 243-bp fragment in the C-terminus of the coat protein coding region. The restriction sites RsaI and AluI were absent from this fragment, which is a feature unique to PPV-C isolates. The restriction sites in 3174-01 were replaced by GTAA/GTGA and GGCA, respectively. There was 95 to 99, 94, 91, and 92 to 94% identity of the 243-bp fragment of 3174-01 with the corresponding region of the strains C, D, EA, and M, respectively. Attempts to detect the virus by RT-PCR using strain C-specific primers in three different approaches were unsuccessful. All molecular techniques assessed in attempting to strain type isolate 3174-01 gave negative results, or results inconsistent for D or M in the case of P3-6K₁ restriction fragment length polymorphism analysis. Isolate 3174-01 reacted in Western blot assay with MAb 5B, with an estimated molecular mass of 32 kDa. No reaction was observed with D-, M-, EA-, or C-specific monoclonal antibodies in Western blot or enzyme-linked immunosorbent assay. The molecular and serological data seem to indicate that PPV isolate 3174-01 does not belong to any of the recognized strains of PPV.

Stationary phase-like properties of the bacteriophage lambda Rex exclusion phenotype

The rex genes of bacteriophage lambda were found to protect lysogenic Escherichia coliK host cells against killing by phage T4 rII, when compared in parallel to isogenic Rex(-) lysogens and nonlysogens. This protective effect was abrogated upon mutation of the host stationary-phase sigma factor RpoS. Rex(+) lysogens infected by T4 rII contracted, formed aggregates and shed flagella, thus resembling cells entering stationary phase. These phenotypes were accentuated in nonlysogenic cells carrying multicopy plasmids expressing rexA-rexB: cells were about two-fold contracted in length, expressed membrane-bound and detached flagella, were insensitive to infection by a variety of phages and clumped extensively; in addition, cultures of these cells were odorous. Our observations support the hypothesis that the Rex system can cause a stationary-phase-like response that protects the host against infection by T4 rII.

Total energy expenditure and body composition changes following peripheral blood stem cell transplantation and participation in an exercise programme

The purpose of this investigation was to assess changes in total energy expenditure (TEE), body weight (BW) and body composition following a peripheral blood stem cell transplant and following participation in a 3-month duration, moderate-intensity, mixed-type exercise programme. The doubly labelled and singly labelled water methods were used to measure TEE and total body water (TBW). Body weight and TBW were then used to calculate percentage body fat (%BF), and fat and fat-free mass (FFM). TEE and body composition measures were assessed pretransplant (PI), immediately post-transplant (PII) and 3 months post-PII (PIII). Following PII, 12 patients were divided equally into a control group (CG) or exercise intervention group (EG). While there was no change in TEE between pre- and post-transplant, BW (P<0.01) and FFM (P<0.05) significantly decreased during the same period. Participation in the exercise programme led to increases in TEE to levels that were both higher than pre- and post-transplant measures (P<0.01). By PIII, the exercising patients also showed gains in FFM (P<0.01) in association with a reduction in %BF (P<0.05). Exercise has a functionally important role in preserving and increasing skeletal mass in the rehabilitation phase of cancer patients.

Signature Tagged Mutagenesis of Haemophilus influenzae identifies genes required for in vivo survival

The pathogenic bacterium Haemophilus influenzae causes meningitis, epiglottitis, pneumonia, otitis media and other infections. To further understand the genetic basis of invasive disease and to inform about the bacterium's requirements in an in vivo environment, we analysed a library of 1632 insertional Tn1545 -Delta3 transposon mutants for their capacity to cause systemic infection in an animal model. We identified 25 genes that are potentially essential for H. influenzae invasive disease, and are candidates for further exploratory research. Seven of the genes encode hypothetical proteins, the function of six of which could be tentatively assigned on the basis of functional motifs and low homology to other bacterial genes. Eleven genes encode central metabolic enzymes or transporters; eight encode proteins that interact with DNA or modify other proteins; and four encode enzymes involved in the elaboration of classical virulence determinants. Two genes have no known function. Independent mutagenesis of six of the 25 genes and determination of the competitive index confirmed that these genes are important or essential to the organism in an in vivo environment. This genome-wide analysis has identified metabolic and other genes required during invasive disease, and the findings may lead to new interventions to prevent and treat H. influenzae infections.

Developing a quality scoring system for epidemiological surveys of genetic disorders

A prototype database of published articles containing data on the frequency of human inherited disorders has been developed for use in clinical contexts, in medical research, for epidemiological studies, and in the planning of genetic services. It can be accessed at http://www.uwcm.ac.uk/uwcm/mg/fidd/. The information available in the literature comes from a wide range of publications, not all can be described primarily as epidemiological surveys. A preliminary assessment indicated that the quality of published articles was highly variable. Very few published articles describe quality-scoring systems for epidemiological surveys in general. We have developed a new scoring system to assess the quality of published articles on genetic disease frequency based on five main criteria and nine component scores. We carried out a first pilot study, to test its feasibility, usefulness and reproducibility. Eleven assessors scored six papers on the epidemiology of Huntington disease. As a result of these findings, we modified the scoring system to define each component more clearly. This was then evaluated in a second pilot study, which utilized six assessors to score 20 papers. The consensus between assessors remained relatively poor. We feel that while it may be possible to improve the scoring system further, the degree of improvement attainable may be limited by the poor standards of content and presentation of published surveys, which led to confusion and uncertainty by assessors. This pilot exercise has shown the need to raise the awareness of researchers and clinicians about the basic quality standards to be required of epidemiological genetic surveys.

Digital imaging versus conventional contact tracing for the objective measurement of venous leg ulcers

OBJECTIVE

This study aimed to compare the accuracy and inter-observer reproducibility of leg ulcer measurements made using digital images and conventional contact tracing.

METHOD

The accuracy of measurements made with these two methods by four observers of 11 shapes with a known area was assessed. The time taken to do this was also measured. Following this, the accuracy and inter-observer reproducibility of the two methods was measured for patients with leg ulcers presenting to the vascular clinic, with contact tracing as the reference.

RESULTS

For the reference shapes, both methods had a mean error of less than 5%. Contact tracing significantly underestimated the area by 3.9% (p < 0.05), while digital tracing showed no significant error. Digital tracing was quicker than contact tracing, especially for larger shapes (p < 0.05). For leg ulcers, there was no significant difference between area measurements made by the two methods. Inter-observer variation of digital tracing was greater for the ulcers than the reference shapes. This was due to differences in subjective interpretation and technical problems in recording some images.

CONCLUSION

Measurement of leg ulcer area using computer-aided tracing of digital camera images is more accurate and quicker than contact tracing provided that appropriate care is taken when taking the pictures. Digital images offer considerable advantages in the shared hospital-community care of patients with leg ulcers.

Multivalent endosome targeting by homodimeric EEA1

Early endosome autoantigen localization to early endosomes is mediated by a C-terminal region, which includes a calmodulin binding motif, a Rab5 interaction site, and a FYVE domain that selectively binds phosphatidyl inositol 3-phosphate. The crystal structure of the C-terminal region bound to inositol 1,3-bisphosphate reveals an organized, quaternary assembly consisting of a parallel coiled coil and a dyad-symmetric FYVE domain homodimer. Structural and biochemical observations support a multivalent mechanism for endosomal localization in which domain organization, dimerization, and quaternary structure amplify the weak affinity and modest specificity of head group interactions with conserved residues. A unique mode of membrane engagement deduced from the quaternary structure of the C-terminal region provides insight into the structural basis of endosome tethering.

Milrinone echocardiographic viability test: a pilot study

We assessed the utility of milrinone to predict recovery of function after surgical myocardial revascularization in patients with severe baseline left ventricular systolic dysfunction caused by coronary artery disease (CAD). Prediction of viable myocardial segments that will regain function after revascularization may help in the selection of patients who will benefit from coronary artery bypass graft surgery (CABG) as well as aid in the choice of target sites for coronary revascularization. We investigated 20 consecutive patients with CAD and left ventricular ejection fraction < or = 40% who had evidence of myocardial viability by either thallium scan or dobutamine viability test and were candidates for elective CABG. Left ventricular regional wall motion and global ejection fraction were assessed by transesophageal echocardiography in the operating room. Measurements were done before and 10 minutes after milrinone infusion, and immediately after CABG. Left ventricular wall motion score was derived by means of a 12-segment model. Functional improvement for each segment was defined as a wall motion change > 1. Baseline ejection fraction was 27% +/- 5% (mean +/- SD). Ejection fraction increased to 35% +/- 5% after milrinone infusion (P < .0001) and to 36% +/- 6% after CABG (P < .0001). Post-CABG ejection fraction was significantly correlated with postmilrinone ejection fraction (r = 0.65, P < .0001). Milrinone infusion resulted in augmentation of contraction in 98 of the 209 abnormal segments (wall motion score > or = 2); 91 (92.9%) of these improved after CABG. One hundred nine of the 111 segments that showed no improvement with milrinone did not improve after revascularization (98.2%). Seventy-three segments were akinetic or dyskinetic at baseline; 46 (63.0%) of these improved with milrinone. Improvement in regional wall motion after revascularization was detected in 84.8% of the segments that improved with milrinone versus only 3.7% of the segments that did not improve with milrinone. In patients with ischemic cardiomyopathy, improvement in left ventricular function (segmental wall motion and global ejection fraction) during milrinone infusion is highly predictive of improvement after CABG.

In vivo-in vitro correlation (IVIVC) modeling incorporating a convolution step

The purpose of in vivo-in vitro correlation (IVIVC) modeling is described. These models are usually fitted to deconvoluted data rather than the raw plasma drug concentration/time data. Such a two-stage analysis is undesirable because the deconvolution step is unstable and because the fitted model predicts the fraction of a dosage unit dissolved/absorbed in vivo which generally is not the primary focus of our attention. Interest usually centers on the plasma drug concentration or some function of it (e.g., AUC, Cmax). Incorporation of a convolution step into the model overcomes these difficulties. Odds, hazards, and reversed hazards models which include a convolution step are described. The identity model (which states that average in vivo and in vitro dissolution/time curves are coincident or directly superimposable) is a special case of these models. The odds model and the identity model were fitted to data sets for two different products using nonlinear mixed effects model fitting software. Results show that the odds model describes both data sets reasonably well and is a significantly better fit than the identity model in each case.

Both CD45R(low) and CD45R(high) "revertant" CD4 memory T cells provide help for memory B cells

During a primary response to thymus dependent antigens, B cells undergo a number of qualitative changes to become memory B cells - processes that require co-stimulatory signals and cytokine help from CD4 T cells. The question of whether distinct, antigen-experienced memory CD4 T cells are subsequently needed to program memory B cells into antibody synthesis has not been clearly resolved. Using an adoptive transfer model in which memory but not naive B cells were stimulated, we evaluated CD4 T cell help using lymphocytes obtained from primed or unprimed thymectomized donors and expressing a naive (CD45R(high)) or a memory (CD45R(low)) phenotype. Memory B cells, most of which were committed to the IgG1 (Th2) subclass, could be stimulated to produce antibody using help transferred by the CD45R(high) naive subset of unprimed donors (slow onset of response), the CD45R(low) subset of 7 day primed donors (large, rapid antibody response) or by both the CD45R(low) and the CD45R(high) "revertant" subsets of 6 month primed donors. We found that antigen primed CD45R(low) CD4 T cells reverted (defaulted) with time to a CD45R(high) resting state, a change that was prevented by persisting antigen. The evidence suggests that CD4 memory T cells are partitioned into two different functional states (CD45R(high) and CD45R(low)) and that these determine the characteristics of the memory B cell response in terms of speed, size and longevity.

Ancestral origins of the Machado-Joseph disease mutation: a worldwide haplotype study

Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disorder originally described in families of Portuguese-Azorean ancestry. The cloning of the MJD1 gene allowed identification of the disease in many other populations, and MJD is now known to be the most common cause of dominant spinocerebellar ataxia. The hypothesis that its present world distribution could result from the spread of an original founder mutation has been raised, both at historical and molecular levels. In the present study, we tested this hypothesis by linkage-disequilibrium analysis of tightly linked polymorphisms and by haplotype comparison, in 249 families from different countries. We typed five microsatellite markers surrounding the MJD1 locus (D14S1015, D14S995, D14S973, D14S1016, and D14S977), and three intragenic single-base-pair polymorphisms (A(669)TG/G(669)TG, C(987)GG/G(987)GG, and TAA(1118)/TAC(1118)). The results show two different haplotypes, specific to the island of origin, in families of Azorean extraction. In families from mainland Portugal, both Azorean haplotypes can be found. The majority of the non-Portuguese families also share the same intragenic haplotype seen in the families coming from the island of Flores, but at least three other haplotypes were seen. These findings suggest two introductions of the mutation into the Portuguese population. Worldwide, the sharing of one intragenic haplotype by the majority of the families studied implies a founder mutation in MJD.

DNA analysis of Duffy genes in American blacks

BACKGROUND

Because limited studies have shown that the Duffy genotype is not accurately reflected by the erythrocyte phenotype, we used PCR-RFLP to determine the true FY1 and FY2 gene frequencies in blacks.

METHODS

Genomic DNA was extracted from 81 randomly selected black individuals, amplified using PCR, digested with BanI and electrophoresed in 1.8% gels. Direct DNA sequencing of the FY regulatory region was done on a sample which had weak Fyb antigens. Standard serological techniques were used to type the erythrocytes for Fya and Fyb.

RESULTS

The most common genotype (83%) in blacks was Fy(a-b+) but almost all of the samples serologically typed as Fy(a-b-). The new gene frequencies are 0.08 for FY1 and 0.92 for FY2. Two donors whose erythrocytes typed weakly positive for Fyb and appeared to be Fyx were homozygous for FY2 by DNA testing. DNA sequencing of the regulatory region for Duffy found a mutation in an Sp1 binding site in the Fyx donor.

CONCLUSIONS

We conclude that (1) the FY2 gene occurs in a much higher frequency in blacks than previously reported which may explain the lack of anti-Fyb in this ethnic group and (2) Fyx appears to be a the product of a mutant FY2 gene giving a quantitative variation in expression.

CAG repeat length in RAI1 is associated with age at onset variability in spinocerebellar ataxia type 2 (SCA2)

Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant disorder caused by the expansion of a polymorphic (CAG)(n) tract, which is translated into an expanded polyglutamine tract in the ataxin-2 protein. Although repeat length and age at disease onset are inversely related, approximately 50% of the age at onset variance in SCA2 remains unexplained. Other familial factors have been proposed to account for at least part of this remaining variance in the polyglutamine dis-orders. The ability of polyglutamine tracts to interact with each other, as well as the presence of intra-nuclear inclusions in other polyglutamine disorders, led us to hypothesize that other CAG-containing proteins may interact with expanded ataxin-2 and affect the rate of protein accumulation, and thus influence age at onset. To test this hypothesis, we used step-wise multiple linear regression to examine 10 CAG-containing genes for possible influences on SCA2 age at onset. One locus, RAI1, contributed an additional 4.1% of the variance in SCA2 age at onset after accounting for the effect of the SCA2 expanded repeat. This locus was further studied in SCA3/Machado-Joseph disease (MJD), but did not have an effect on SCA3/MJD age at onset. This result implicates RAI1 as a possible contributor to SCA2 neurodegeneration and raises the possibility that other CAG-containing proteins may play a role in the pathogenesis of other polyglutamine disorders.

Translational frameshift sites within bacteriophage lambda genes rexA and cI

Phage lambda's cI-rexA-rexB operon displays an intriguing example of regulation by an unexplained mechanism of polarity. We have identified three potential -1 translational frameshift sites and present a model for translational frameshift suppression by lambda's CI repressor as a mechanism of regulating operon polarity, implying an additional role for CI self-regulation.

Education of physicians-in-training can decrease the risk for vascular catheter infection

BACKGROUND

Procedure instruction for physicians-in-training is usually nonstandardized. The authors observed that during insertion of central venous catheters (CVCs), few physicians used full-size sterile drapes (an intervention proven to reduce the risk for CVC-related infection).

OBJECTIVE

To improve standardization of infection control practices and techniques during invasive procedures.

DESIGN

Nonrandomized pre-post observational trial.

SETTING

Six intensive care units and one step-down unit at Wake Forest University Baptist Medical Center, Winston-Salem, North Carolina.

PARTICIPANTS

Third-year medical students and physicians completing their first postgraduate year.

INTERVENTION

A 1-day course on infection control practices and procedures given in June 1996 and June 1997.

MEASUREMENTS

Surveys assessing physician attitudes toward use of sterile techniques during insertion of CVCs were administered during the baseline year and just before, immediately after, and 6 months after the first course. Preintervention and postintervention use of full-size sterile drapes was measured, and surveillance for vascular catheter-related infection was performed.

RESULTS

The perceived need for full-size sterile drapes was 22% in the year before the course and 73% 6 months after the course (P < 0.001). The perceived need for small sterile towels at the insertion site decreased reciprocally (P < 0.001). Documented use of full-size sterile drapes increased from 44% to 65% (P < 0.001). The rate of catheter-related infection decreased from 4.51 infections per 1000 patient-days before the first course to 2.92 infections per 1000 patient-days 18 months after the first course (average decrease, 3.23 infections per 1000 patient-days; P < 0.01). The estimated cost savings of this 28% decrease was at least $63000 and may have exceeded $800000.

CONCLUSIONS

Standardization of infection control practices through a course is a cost-effective way to decrease related adverse outcomes. If these findings can be reproduced, this approach may serve as a model for physicians-in-training.

Translational frameshift sites within bacteriophage lambda genes rexA and cI

Phage lambda's cI-rexA-rexB operon displays an intriguing example of regulation by an unexplained mechanism of polarity. We have identified three potential -1 translational frameshift sites and present a model for translational frameshift suppression by lambda's CI repressor as a mechanism of regulating operon polarity, implying an additional role for CI self-regulation.

The role of audit in making do not resuscitate decisions

Audit has been proposed as a useful means of implementing and evaluating 'Do Not Resuscitate (DNR)' policies. This paper explores the background to the introduction of DNR policies and reviews published reports of their use in clinical practice. Problems with auditing and implementing DNR policies are highlighted.

Audit of resuscitation decisions has little impact on clinical practice

OBJECTIVE

To determine if clinical audit leads to sustained improvement in resuscitation decision-making.

METHOD

Analysis of data from five studies performed over nine years between 1989 and 1998. Two of the surveys included all medical and elderly patients, while three surveys in 1993, 1994 and 1996 included only patients over 75 years of age.

RESULTS

The three surveys involving only elderly patients revealed significant improvement in recording the decisions made on resuscitation (73% vs 50%; p = 0.02) over a two-month audit cycle, but this improvement was not maintained. Clinical audit and the use of a proforma improved neither the practice of discussing resuscitation with patients nor the involvement of consultants in the decision-making process over the nine-year period.

CONCLUSION

Clinical audit may lead to short-term improvements in resuscitation decision-making, but this improvement does not appear to be sustained over time. Other measures need to be considered to improve practice in this area.

Study of three intragenic polymorphisms in the Machado-Joseph disease gene (MJD1) in relation to genetic instability of the (CAG)n tract

Intergenerational instability is one of the most important features of the disease-associated trinucleotide expansions, leading to variation in size of the repeat among and within families, which manifests as variable age at onset and severity, and is probably the basis for the occurrence of anticipation. Several factors are known to affect the degree of instability, namely the type of repeated sequence, its initial size, the presence or absence of interruptions in the repetitive tract and the gender of the transmitting parent. A recent study demonstrated the effect of an intragenic polymorphism (C987GG/G987GG) in the Machado-Joseph disease causative gene, immediately downstream of the CAG repeat, on the intergenerational instability of the expanded repeat. Surprisingly, there was an effect not only of the specific allele in cis to the disease chromosome, but also of the allele on the normal chromosome, suggesting the existence of an interaction between the normal and expanded alleles that affects the fidelity of replication of the (CAG)n tract. This effect could be a direct effect of the polymorphism studied or, alternatively, this polymorphism could be in disequilibrium with some other flanking sequence which affects the instability of the repetitive (CAG)n tract. In order to confirm the previous results in a different population and to distinguish between a direct and indirect effect of the CGG/GGG polymorphism, we typed 70 parent-progeny pairs for which the variation in the (CAG)n length in the MJD1 gene was known, for three intragenic polymorphisms: C987GG/G987GG and two additional, newly described ones, TAA1118/TAC1118 and A669TG/G669TG. We also typed a control population of 125 individuals for the A669TG/G669TG, C987GG/G987GG and TAA1118/TAC1118 polymorphisms, in an attempt to identify any association between haplotype and (CAG)n length in normal chromosomes, suggestive of an instability-predisposing effect of the repeat-flanking sequences, which could have led to the origin of the MJD mutation in the human population. We confirmed the effect of the C987GG/G987GG polymorphism on intergenerational instability when present in trans. Our results suggest that this effect is restricted to a small region of the gene, immediately downstream of the CAG repeat, which includes this particular nucleotide substitution and the stop codon of the MJD1 cDNA, and is not a more widespread chromosomal effect. The lack of a significant association of any specific intragenic haplotype with larger CAG repeats in normal chromosomes, together with the absence of an effect of the intragenic haplotype in cis on the intergenerational instability of the expanded (CAG)n in MJD families does not indicate the existence of an instability-predisposing haplotype.

Undercooked hens eggs remain a risk factor for sporadic Salmonella enteritidis infection

The prevalence of salmonella contamination in hens' eggs remains high. A case control study of sporadic cases of Salmonella enteritidis infection in Wales in 1997 confirmed the association of infection with consumption of raw or lightly cooked eggs.

Acquired mutations in phage lambda genes O or P that enable constitutive expression of a cryptic lambdaN+cI[Ts]cro- prophage in E. coli cells shifted from 30 degreesC to 42 degreesC, accompanied by loss of immlambda and Rex+ phenotypes and emergence of a non-immune exclusion-state

The majority of bacteria, which carry the N+-cI857[Ts]-cro--O+-P+ fragment of lambda genome, are killed when derepressed by shifting from 30 degreesC to 42 degreesC. Among rare survivors, we observed a proportion of colony-forming units (cfu) that retained the typical immlambda-immunity phenotype when grown at 30 degreesC; however, when shifted from 30 degreesC to 42 degreesC, they lost lambda immunity and acquired a non-immune exclusion-state (Nie phenotype). We also found that the immlambda survivor cfu quickly lost their Rex+ exclusion phenotype (as measured by T4rII plating inhibition) when shifted from 30 degreesC to 42 degreesC, even though they produced CII, which stimulates pE-cI-rexA-rexB transcription. The Nie phenotype was characterized by an inhibition of plating of the homoimmune phage, lambdawt, and the heteroimmune phage, lambdaimm434. However, lambdavir and spontaneous mutants of lambdawt (lambdase mutations localized within oR) escaped the Nie exclusion-state and plated efficiently on lawns of Nie cfu at 42 degreesC. Thus, we examined the scope of the Nie exclusion-state toward lambda mutants blocked for lysogeny, and lambda hybrids substituted for immunity or replication genes. Phage like lambdawt, competent for lysogeny, were severely excluded compared to some mutants of lambda defective for lysogeny. Among this latter type, there was high variance in the Nie exclusion of various cI mutants; some of which were not excluded. The Nie exclusion-state was attributed to the constitutive expression of the defective lambda fragment in the survivor cfu, made possible by the acquired replication defect(s). We characterized, both genetically and physically, the mutations in the defective integrated lambda prophage that permitted growth of the survivor cfu at 42 degreesC. In five of seven survivor cfu, we identified IS2 insertions within lambda genes O and P that can block replication initiation from the lambda fragment. The remaining survivor cfu had multiple base substitutions within the C-terminal end of O and N-terminal half of P, the majority of which were silent. In some of these mutants, either an ochre nonsense mutation or a single-base frameshift deletion inactivated P.

Do general practitioners know when living wills are legal?

BACKGROUND

There is growing public awareness of living wills or advance directives. Patients who wish to make advance directives may approach general practitioners (GPs) for advice. However, many GPs are unaware of the correct legal status of living wills.

METHODS

Questionnaires were sent to 270 GPs in London and Winchester, asking seven questions about the current legal status of living wills.

RESULTS

Of the 214 GPs (79%) who returned questionnaires, only 104 (49%) were aware that some types of advance directives could carry legal force. Many of the GPs who did know that living wills could be legally binding were unable correctly to answer further questions on the practicalities of the law; for example, 26% were wrong in believing that a lawyer had to draw up a living will, and 13% incorrectly believed that a doctor was legally required to give any treatment requested by a patient in a living will.

CONCLUSIONS

Half of the GPs surveyed were unaware that living wills currently have legal force and most of the rest were unaware of important details of the law. More attention needs to be given to the education of doctors in this area.

Analysis of SCA1, DRPLA, MJD, SCA2, and SCA6 CAG repeats in 48 Portuguese ataxia families

The spinocerebellar ataxias (SCAs) are clinically and genetically a heterogeneous group of neurodegenerative disorders. To date, eight different loci causing SCA have been identified: SCA1, SCA2, Machado-Joseph disease (MJD)/SCA3, SCA4, SCA5, SCA6, SCA7, and dentatorubropallidoluysian atrophy (DRPLA). Expansion of a CAG repeat in the disease genes has been found in five of these disorders. To estimate the relative frequencies of the SCA1, DRPLA, MJD, SCA2, and SCA6 mutations among Portuguese ataxia patients, we collected DNA samples from 48 ataxia families and performed polymerase chain reaction (PCR) amplification of the CAG repeat mutations on chromosomes 6p, 12p, 14q, 12q, and 19p, respectively. Fifty-five individuals belonging to 34 dominant families (74%) had an expanded CAG repeat at the MJD gene. In five individuals from two kindreds with a dominant pattern of inheritance (4%), an expanded CAG repeat at the SCA2 gene was found. In MJD patients, the normal allele size ranged from 13 to 41, whereas the mutant alleles contained 65 to 80 repeats. For the SCA2 patients, normal alleles had 22 or 23, while expanded alleles had between 36 and 47 CAG units. We did not find the SCA1, DRPLA, or SCA6 mutations in our group of families. The MJD mutation remains the most common cause of SCA in Portugal, while a small number of cases are caused by mutations at the SCA2 gene, and 22% are due to still unidentified genes.