Enhancement of equine infectious anemia virus virulence by identification and removal of suboptimal nucleotides

Pathogenicity was reportedly restored to an avirulent molecular clone of equine infectious anemia virus (EIAV) by substitution of 3' sequences from the pathogenic variant strain (EIAV(PV)). However, the incidence of disease in horses/ponies was found to be significantly lower (P = 0.016) with the chimeric clone (EIAV(UK)) than with EIAV(PV). This was attributable to 3' rather than 5' regions of the proviral genome, where EIAV(UK) differs from the consensus EIAV(PV) sequence by having a 68-bp duplication in the 3' LTR and arginine (R(103)) rather than tryptophan (W(103)) at position 103 in the second exon of rev. In EIAV(UK) recipients the duplication was rapidly eliminated and R(103) replaced by W(103) in the viral population. Furthermore, removal of the 3' variant sequences from EIAV(UK) (EIAV(UK3)) resulted in an equivalent (P = 0.013) disease potential in Equus caballus to EIAV(PV). The 68-bp duplication and/or R(103) may limit peak viral RNA accumulation during acute infection.     

Reducing delirium in elderly patients with hip fracture: a multi‐factorial intervention study

Background: There is an evident need for improved management of elderly patients with trauma in order to avoid common and troublesome complications such as delirium. The aim of this study was to investigate whether an implementation of a multi‐factorial program including intensified pre‐hospital and perioperative treatment and care could reduce the incidence of delirium in elderly patients with hip fracture, cognitively intact at admission to the hospital. In addition, we explored the factors that characterize patients who developed delirium. Methods: A prospective, quasi‐experimental design was used. A total of 263 patients with hip fracture (≥65 years), cognitively intact at admission, were consecutively included between April 2003 and April 2004. On 1 October 2003, a new program was introduced. All patients were screened for cognitive impairment within 30 min after admission to the emergency department using The Short Portable Mental Status Questionnaire (SPMSQ). To screen for delirium, patients were tested within 4 h of admission and thereafter daily, using the Organic Brain Syndrome scale. Results: The number of patients who developed delirium during hospitalization was 74 (28.1%), with a decrease from 34% (45 of 132) in the control group to 22% (29 of 131) in the intervention group (P=0.031). Patients who developed delirium were statistically older, more often had >4 prescribed drugs at admission and scored less well in the SPMSQ test. Conclusion: The use of a multi‐factorial intervention program in elderly hip fracture patients, lucid at admission, reduced the incidence of delirium during hospitalization by 35%.     

Low-dose Cyclopenthiazide in the Treatment of Hypertension: A One-year Community-based Study

After an 8-week placebo period, 73 patients whose diastolicblood pressures were between 90 and 110 mmHg were randomly assignedto receive 125 µg (low dose) or 500 µg of cyclopenthiazide(standard dose) for a period of one year. Blood pressure wasmeasured in the patient's home by the same observer at two-weeklyintervals during an 8-week placebo run-in period, every 4 weeksfor a further 12 weeks and at 24, 36 and 52 weeks thereafter.Serum potassium, urate, glucose, glycosylated haemoglobin, totaland HDL cholesterol, and apolipoproteins were measured at theend of the placebo period and at 4, 8, 24 and 52 weeks of activetreatment. Twelve of the 73 patients had an inadequate antihypertensiveresponse—five on the higher dose and seven on the lowerdose. One patient receiving 500 µg was withdrawn becauseof adverse effects. In the remaining 60 patients, systolic anddiastolic blood pressures were significantly reduced when comparedwith pretreatment values in both treatment groups throughoutthe one year period. The decreases in blood pressure were notsignificantly different from each other (p>0.65). Three patientson 500 µg required potassium supplements. Maximum decreasesin the serum potassium of 0.52 mmol/l(500 µg dose) and0.14 mmol/l(125 µg dose) were observed at 24 weeks oftreatment in the remaining 57 patients. The differences betweenthe two doses at this time were statistically significant (p< 0·05), as were the increases in serum urate observedat 4, 8 and 24 weeks (p<0.05). Five hundred micrograms ofcyclopenthiazide increased total serum cholesterol at eightand 24 weeks (0.35, 0.36 mmol/l respectively) when comparedwith pretreatment values (p<0.01) and almost achieved statisticalsignificance when compared with the corresponding low dose value(p = 0.066). This study confirms that 125 µg of cyclopenthiazideis a useful antihypertensive agent with a favourable metabolicprofile which is maintained in the long term.     

Serological confirmation of human T-lymphotropic virus type I infection in healthy blood and plasma donors

We wished to develop criteria for serological confirmation of human T- lymphotropic virus type I (HTLV-I) infection in healthy donors. Selected serum or plasma samples reactive by HTLV-I enzyme immunosorbent assay or gel-agglutination assays with at least one viral- specific band on Western immunoblot (WIB) were tested in six laboratories by four WIBs and four radioimmunoprecipitation assays (RIPAs) for antibodies to HTLV-I proteins encoded by gag (p19 and p24), env (gp46 and/or gp61), and tax (p40x) genes. One hundred forty-two donor sera were obtained from 38 Japanese, 69 American, and 35 Caribbean blood or plasma donors. Among these samples, WIB assays appeared more sensitive to p24 antibodies, whereas RIPAs were significantly more sensitive to gp61 antibodies. All sera (137) with gp61 antibodies had p24 antibodies. Of the 137 sera positive for p24 and gp61 antibodies, p19 antibodies were detected in 129 sera, and p40x antibodies were detected in 108. In sera with p19 antibodies and antibodies to env- or tax-encoded proteins, p24 antibodies were always present. Antibodies to p40x were not found in the absence of gp61 antibodies. Virological evidence of infection was found in seven American donors by lymphocyte coculture (one HTLV-I, one HTLV-II) or by polymerase chain reaction (three HTLV-I, two HTLV-II). Sera from all seven donors showed p24 and gp46 and/or gp61 antibodies. We suggest that seroreactivity to both p24 and gp46 and/or gp61 by WIB or RIPA or both are suitable criteria to confirm but not to distinguish HTLV-I and HTLV-II infections.     

Point mutations in the conserved box 1 region inactivate the human granulocyte colony-stimulating factor receptor for growth signal transduction and tyrosine phosphorylation of p75c-rel

The human granulocyte colony-stimulating factor receptor (hG-CSFR) belongs to the cytokine receptor superfamily. As with other members of this family, the cytoplasmic domain of hG-CSFR lacks intrinsic tyrosine kinase activity. To identify critical regions mediating growth signal transduction by hG-CSFR, deletions or site-directed amino acid substitutions were introduced into the cytoplasmic domain of hG-CSFR, and the mutant cDNAs were transfected into the murine interleukin-3 (IL- 3)-dependent Ba/F3 and FDCP cell lines. Truncation of the carboxy- terminal end of the receptor to the membrane-proximal 53 amino acids of the cytoplasmic domain, which retained the conserved Box 1 and Box 2 sequence motifs, decreased the ability of hG-CSFR to transduce G-CSF- mediated growth signals without an associated loss in receptor binding affinity. Substitution of proline by alanine at amino acid positions 639 and 641 within Box 1 completely abolished the G-CSF-mediated growth signal. Rapid induction of tyrosine phosphorylation of several cellular proteins, including a 75-kD protein (p75) identified as c-rel, was an early event associated with transduction of proliferative signals by hG- CSFR in Ba/F3 transfectants. Mutant receptors containing Pro-to-Ala substitutions that inactivated the receptor for mitogenic activity also inactivated the receptor for tyrosine-specific phosphorylation of p75. These results show that the conserved Box 1 sequence motif (amino acids 634 to 641) is critical for mitogenesis and activation of cellular tyrosine kinases by hG-CSFR.     

Repeatability and reproducibility of Cobra HD fundus camera meibography in young adults with and without symptoms of dry eye

Purpose

The inter-session repeatability (ISR), inter-examiner reproducibility (IER) and within-subject variability (WSV) of the Cobra HD fundus camera meibographer were examined in participants with and without dry eye symptoms.

Methods

Symptoms were determined based on Ocular Surface Disease Index scores (≥13 being considered symptomatic), and subgroups were compared using the Mann–Whitney U-test. Images of meibomian glands (MGs) from the upper and lower right eyelids were captured by two examiners on the same day (S1) to determine IER. One examiner repeated the measurements on a second day (S2) to obtain the ISR. ISR, IER and WSV were calculated using Friedman, correlation tests and Bland and Altman analyses with mean differences (md) and 95% confidence intervals (CIs), within-subject standard deviations (Sw) and intra-class correlation coefficients (ICC).

Results

The ISR experiment included 72 participants (mean age: 23 ± 5 years, range: 19–43, 36 symptomatic). Mean MG loss of the upper (S1: 13.5 ± 9.5%, S2: 12.8 ± 8.5%) and lower eyelids (S1: 7.5 ± 6.9%, S2: 7.3 ± 6.3%) was not significantly different between sessions for all participants, symptomatic and asymptomatic subgroups for both eyelids. The ISR Sw for the upper and lower eyelids was 1.3% and 1.0%; md was 0.7 ± 3.5% (CI:−6.25% to 7.62%) and 0.1 ± 2.1% (CI: −3.94% to 4.17%), respectively. The IER experiment included 74 participants (mean age: 23 ± 5 years, range: 19–43, 37 symptomatic). Mean MG loss of the upper (Examiner 1: 12.7 ± 8.2%, Examiner 2: 13.1 ± 8.0%) and lower eyelids (Examiner 1: 7.0 ± 6.2%, Examiner 2: 7.4 ± 6.2%) was not significantly different between examiners for all participants, symptomatic and asymptomatic subgroups for both eyelids. The IER ICC values were >0.86 for all conditions, Sw was 1.3% and 1.2%, with a md of −0.4 ± 3.2% (CI: −6.65% to 5.90%) and −0.4 ± 2.9% (CI: −6.15% to 5.31%), respectively. The WSV Sw values were <1.4%, and ICC values were >0.89 for both eyelids, examiners and experimental sessions.

Conclusions

The Cobra HD fundus camera demonstrates good repeatability, reproducibility and low WSV, and is a reliable clinical instrument for meibography.